A dataset provided by the European Space Agency

Name VEX-V-VRA-1-2-3-EXT2-0646
Mission VENUS-EXPRESS
URL https://archives.esac.esa.int/psa/ftp//VENUS-EXPRESS/VRA/VEX-V-VRA-1-2-3-EXT2-0646-V1.0
DOI https://doi.org/10.5270/esa-phewhup
Author European Space Agency
Abstract This is a Venus Express Radio Science data set, collected during the Extended Mission Phase 3 (EXT3) 2010-08-22 to 2012-12-31 science subphase 44 (MTP81) 2012-06-24 to 2012-07-22. It is a Occultation measurement and covers the time 2012-06-30T01:10:00.050 to 2012-06-30T02:20:26.949. This data set contains archival raw, processed, and supporting radio science Doppler data acquired from the Venus Express Radio Science Experiment (VeRa). The data were recorded using the closed loop and open loop receiver facilities at the European Space Agency (ESA) or at the NASA Deep Space Network (DSN) groundstations. The data set contains one Venus measurement recorded in earth occultation geometry starting before the ingress (ingoing) phase and ending after the egress (outgoing) phase of the occultation pass. The data can be used to derive electron density profiles in the ionosphere and profiles of neutral number density, pressure and temperature in the neutral atmosphere of Venus. The neutral atmosphere profiles deduced from these occultation measurements usually cover the altitude range between about 45 - 90 km.
Description Data Set Overview The Venus Express (VEX) Radio Science (VeRa) Data Archive is a time-ordered collection of raw and partially processed data collected during the Venus Express Mission. This is a Occultation measurement covering the time 2012-06-30T01:10:00.050 to 2012-06-30T02:20:26.949. This data set contains archival raw, partially processed, and ancillary/supporting radio science data acquired during the Routine Operations phase of the Venus Express (VEX) mission using ground facilities of the European Space Agency (ESA) and/or the NASA Deep Space Network (DSN). VeRa radio occultation observations start shortly before the occultation ingress, when the VEX spacecraft moves behind the planetary disk as seen from the Earth and stop shortly after the occultation egress, when the probe emerges from behind the planet. VeRa occultation data usually cover three recording phases: the occultation ingress (1), the time when the spacecraft is occulted by the planet (2) and the occultation egress (3). The different observation phases can be distinguished by regarding the AGC data, which records the strength of the received signal. In phase (1) and (3) the AGC level is high compared to phase (2). In Phase (2) still a signal may be received at the groundstation due to the strong bending of the radio waves in the dense atmosphere. The strength of the signal is significantly reduced and weakens further the deeper the radio waves penetrate the atmosphere until the groundstation may be unable to lock. Therefore, the beginning of phase (2) is recognized at first order by a sharp drop of the AGC down to -95 dB and lower and ends with a sharp rise in the AGC data back to the former AGC level. For the derivation of higher science products it is recommended to divide the level 2 data into an ingress and an egress part and to process these data seperatetly. This data set was collected during the VEX science subphase 44 (M...TP81) 2012. For more information see MISSION.CAT. Mission Phase Definition ------------------------ The mission phases which are used in the Data Set Identifier 'DATA_SET_ID' correspond to the following table: Phase name | abbreviation | time span Nominal Mission Phase | NMP | 2005-11-09 - 2007-10-02 ---------------------------------------------------------------Extended Mission 1 | EXT1 | 2007-10-03 - 2009-05-31 ---------------------------------------------------------------Extended Mission 2 | EXT2 | 2009-06-01 - tbd The mission phases are further divided into science subphases. Mission phase and science subphase definitions can be found in CATALOG/MISSION.CAT and DOCUMENT/ESA_DOC/VEX_ARCHIVE_CONVENTIONS.PDF. Data files ---------- Data files are: the tracking files from Deep Space Network (DSN) and from the Intermediate Frequency Modulation System (IFMS) used by the ESA ground station New Norcia, Level 1a to level 2 data are archived, the predicted and reconstructed Doppler and range files, the Geometry files. All Level 1a binary data files will have the file name extension eee = .DAT IFMS Level 1a ASCII data files will have the file name extension eee = .RAW Level 1b and 2 tabulated ASCII data files will have the file name extension eee = .TAB Binary data files will have the file name extension .DAT Data levels ----------- It should be noted that these data levels which are also used in the file names and data directories are PSA data levels whereas in the PDS label files CODMAC levels are used. PSA data level | CODMAC level ----------------------------- 1A | 1 1B | 2 2 | 3 Data Set Identifier ------------------- The 'DATA_SET_ID' is a unique alphanumeric identifier for the data sets. It looks something like: XXX-Y-ZZZ-U-VVV-NNNN-WWW Acronym | Description | Example -------------------------------------------------------- XXX | Instrument Host ID | VEX -------------------------------------------------------- Y | Target ID | V (for Venus) or X for | | others like for example | | the sun during solar | | conjunction measurements -------------------------------------------------------- ZZZ | Instrument ID | VRA -------------------------------------------------------- U | Data level (here | 1/2/3 (Data set | CODMAC levels are used) | contains raw, edited | | and calibrated data) --------------------------------------------------------- VVV | VRA mission phase | VOI --------------------------------------------------------- NNNN | 4 digit sequence number | 0123 | which is identical to | | the Radio Science | | Volume_id | --------------------------------------------------------- WWW | Version number | V1.0 VeRA data were originally archived as volumes rather than data sets. However, ESA PSA does not uses volume but data sets. To avoid confusion it was specified that one VeRa data volume is equal one data set. Thus the data set was also assigned a 4 digit sequence number which is identical to the one used in the Radio Science volume_id. If the data_set_id is known it is automatically specified on which volume the data set is found. VOLUME_ID --------- The VOLUME_ID is a unique alphanumeric identifier for volume. The Volume ID provides a unique identifier for a single MaRS, RSI or VeRa data volume, typically a physical CD-ROM or DVD. The volume ID is also called 'volume label' by the various CDROM recording software packages. The Volume ID is formed using a mission identifier, an instrument identifier of 3 charac- ters, followed by an underscore character, followed by a 4 digit sequence number. In the 4-digit number, the first one represents the volume set, the remaining digits define the range of volumes in the volume set. For Mars Express the first digit is not defined after the kind of measurement (see below for Rosetta and VEX), but after the Mission phase. 0000: Commissioning 1000: Occultation 2000: Gravity 3000: Solar Conjunction 4000: Bistatic Radar 5000: Passive/Active Checkouts 6000: Swing-bys/Fly-bys 7000: Cometary Coma Observations It looks something like: XXXXXX-ZZZZ Acronym | Description | Example ---------------------------------------------------------- XXXXXX | Instrument Host and Instrument ID | VEXVRA ---------------------------------------------------------- ZZZZ | 4 digit sequence number | 0123 Important note: the here defined ESA PSA Volume_Id is not identical with the Radio Science Volume_Id. The Radio Science Volume_Id is a number which is incremented measurement by measurement, independent what kind of measurement was conducted. The Radio Science Volume_Id belonging to one single measurement can be find in the Logbook, loca- ted in the folder DOCUMENT/VRA_DOC. Descriptive files ----------------- Descriptive files contain information in order to support the processing and analysis of data files. The following file types are defined as descriptive files with extension eee = .LBL PDS label files .CFG IFMS configuration .AUX Anxiliary files (event files, attitude files, ESOC orbit files, products, SPICE files) .TXT Information (text) files File naming convention All incoming data files will be renamed and all processed data files will be named after the following file naming convention format. The original file name of the incoming tracking data files will be stored in the according label file as source_product_id. The new PDS compliant file name will be the following: rggttttlll_sss_yydddhhmm_qq.eee Acronym | Description | Examples = r | space craft name abbreviation | V | R = Rosetta | | M = Mars Express | | V = Venus Express | ------------------------------------------------------------- gg | Ground station ID: | 43 | | | 00: valid for all ground stations; | | various ground stations or independent | | of ground station or not feasible to | | appoint to a specific ground station or | | complex | | | | DSN complex Canberra: | | --------------------- | | 34 = 34 m BWG (beam waveguide) | | 40 = complex | | 43 = 70 m | | 45 = 34 m HEF (high efficiency) | | | | ESA Cebreros antenna: | | --------------------- | | 62 = 35 m | | | | DSN complex Goldstone: | | ---------------------- | | 10 = complex | | 14 = 70 m | | 15 = 34 m HEF | | 24 = 34 m BWG | | 25 = 34 m BWG | | 26 = 34 m BWG | | 27 = 34 m HSBWG | | | | ESA Kourou antenna: | | ------------------- | | 75 = 15 m | | | | DSN complex Madrid: | | ------------------- | | 54 = 34 m BWG | | 55 = 34 m BWG | | 63 = 70 m | | 65 = 34 m HEF | | 60 = complex | | | | ESA New Norcia antenna: | | ----------------------- | | 32 = 35 m | ------------------------------------------------------------- tttt | data source identifier: | TNF0 | | | Level 1A and 1B: | | ---------------- | | ODF0 = ODF closed loop | | TNF0 = TNF closed loop (L1A) | | T000-T017 = TNF closed loop (L1B) | | ICL1 = IFMS 1 closed loop | | ICL2 = IFMS 2 closed loop | | ICL3 = IFMS RS closed loop | | IOL3 = IFMS RS open loop | | R1Az = RSR block 1A open loop | | R1Bz = RSR block 1B open loop | | R2Az = RSR block 2A open loop | | R2Bz = RSR block 2B open loop | | R3Az = RSR block 3A open loop | | R3Bz = RSR block 3B open loop | | z=1...4 subchannel number | | ESOC = ancillary files from ESOC DDS | | DSN0 = ancillary files from DSN | | SUE0= ancillary and information files | | coming from Stanford University | | center for radar astronomy | | | | Level 2: | | ------- | | UNBW = predicted and reconstructed | | Doppler and range files | | ICL1 = IFMS 1 closed loop | | ICL2 = IFMS 2 closed-loop | | ICL3 = IFMS RS closed-loop | | ODF0 = DSN ODF closed loop file | | T000-T017 = TNF closed loop file | | RSR0 = DSN RSR open loop file | | RSRC = DSN RSR open loop file containing | | data with right circular | | polarization (only solar | | conjunction measurement) | | RSRL = DSN RSR open loop file containing | | data with left circular | | polarization (only solar | | conjunction measurement) | | NAIF = JPL or ESTEC SPICE Kernels | | SUE0 = ancillary information and | | calibration files coming from | | Stanford University center for | | radar astronomy | | GEOM = geometry file | | | --------|------------------------------------------|-------- lll | Data archiving level | L1A | L1A = Level 1A | | L1B = Level 1B | | L02 = Level 2 | | L03 = Level 3 | --------|------------------------------------------|-------- sss | data type | | | | IFMS data files level 1A: | | ------------------------- | | D1X uncalibrated Doppler 1 X-Band | | D1S uncalibrated Doppler 1 S-Band | | D2X uncalibrated Doppler 2 X-Band | | D2S uncalibrated Doppler 2 S-Band | | C1X Doppler 1 X-Band equip. calibration | | C1S Doppler 1 S-Band equip. calibration | | C2X Doppler 2 X-Band equip. calibration | | C2S Doppler 2 S-Band equip. calibration | | RGX uncalibrated X-Band range | | RGS uncalibrated S-Band range | | MET meteo file | | AG1 AGC 1 files | | AG2 AGC 2 files | | RCX X-Band range equip. calibration | | RCS S-Band range equip. calibration | | | | DSN data files level 1A: | | ------------------------- | | ODF original orbit files (closed loop) | | RSR radio science receiver open-loop file| | TNF file (closed loop) | | | | ESOC ancillary data level 1A: | | ----------------------------- | | ATR attitude file, reconstructed | | EVT orbit event file | | OHC orbit file, heliocentric cruise | | OVO orbit file, venuscentric, operational| | | | DSN Calibration files level 1A: | | ------------------------------- | | TRO DSN tropospheric calibration model | | MET DSN meteorological file | | ION DSN ionospheric calibration model | | BCL SUE Bistatic radar temperature | | calibration | | | | DSN ancillary data level 1A: | | ----------------------------- | | DKF DSN Keyword File | | MON DSN monitor data | | NMC DSN Network Monitor and Control file | | SOE DSN Sequence of Events | | EOP DSN earth orientation parameter file | | ENB SUE Experimenter Notebook | | MFT SUE Manifest files | | LIT DSN Light time file | | HEA DSN Data collection list | | OPT DSN Orbit and timing geometry file | | | | DSN Browse Plots level 1A: | | -------------------------- | | BRO bistatic radar 4-panel plots (browse)| | | | IFMS data files level 1B: | | ------------------------- | | D1X uncalibrated Doppler 1 X-band | | D1S uncalibrated Doppler 1 S-band | | D2X uncalibrated Doppler 2 X-band | | D2S uncalibrated Doppler 2 S-band | | C1X Doppler 1 X-band equip. calibration | | C1S Doppler 1 S-band equip. calibration | | C2X Doppler 2 X-band equip. calibration | | C2S Doppler 2 S-band equip. calibration | | RGX uncalibrated X-band range | | RGS uncalibrated S-band range | | MET meteo | | AG1 AGC 1 | | AG2 AGC 2 | | RCX X-band range equip. calibration | | RCS S-band range equip. calibration | | | | DSN ODF data files level 1B: | | ----------------------------- | | DPS S-band Doppler | | DPX X-band Doppler | | RGS uncalibrated S-Band ranging file | | RGX uncalibrated X-Band ranging file | | RMP uplink frequency ramp rate file | | | | DSN calibration data level 1B: | | ----------------------------- | | MET meteorological file | | | | IFMS data level 2: | | ----------------- | | D1X uncalibrated Doppler 1 X-Band | | D1S uncalibrated Doppler 1 S-Band | | D2X uncalibrated Doppler 2 X-Band | | D2S uncalibrated Doppler 2 S-Band | | RGX uncalibrated X-Band range | | RGS uncalibrated S-Band range | | RCX X-Band range equip. calibration | | RCS S-Band range equip. calibration | | | | IFMS Browse plots level 2 | | ------------------------- | | B1X Quick look plots of calibrated | | Doppler 1 X-band | | B1S Quick look plots of calibrated | | Doppler 1 S-band | | B2X Quick look plots of calibrated | | Doppler 2 X-band | | B2S Quick look plots of calibrated | | Doppler 2 S-band | | | | DSN level 2 data: | | ----------------- | | DPX calibrated Doppler X-band | | DPS calibrated Doppler S-band | | RGS calibrated S-band ranging file | | RGX calibrated X-band ranging file | | BSR bistatic radar power spectra | | SRG bistatic radar surface reflection | | geometry file | | | | DSN level 2 calibration data: | | ---------------------------- | | SRF Surface Reflection Filter Files | | | | orbit files level 2: | | -------------------- | | PTW Doppler & range prediction two-way | | PON Doppler & range prediction on | | RTW reconstructed Doppler & range orbit | | file two-way | | RON reconstructed Doppler & range orbit | | file one-way | | LOC heliocentric state vector file | | | | Constellation file Level 2: | | --------------------------- | | MAR Mars constellation file | | VEN Venus constellation file | | P67 Churyumov-Gerasimenko | | constellation file | | | | SPICE kernel files level 2: | | --------------------------- | | BSP binary spacecraft/location | | kernel file | | FRM frame kernel file | | ORB orbit numbering file | | PBC predicted attitude kernel file | | PCK planetary constant kernel | | SCK space craft clock kernel | | TLS leap second kernel file | | | | Science data level 3: | | --------------------- | | SCP solar corona science | --------|------------------------------------------|-------- yy | Year | 05 --------|------------------------------------------|-------- ddd | Day of year | 153 --------|------------------------------------------|-------- hhmm | Sample hour, minute start time | 1135 | For IFMS files this is the ESOC | | reference time tag which usually | | coincides with the first sample time. | | For IFMS Ranging files however this is | | not true. Here the reference time tag | | is two-way light time before the first | | actual measurement. | --------|------------------------------------------|-------- qq | Sequence or version number | 01 --------|------------------------------------------|-------- eee | .DAT binary files (Level 1A) | .RAW | .TAB ASCII table data file | | .AUX ancillary file | | .CFG IFMS configuration file (Level 1B) | | .LBL PDS label files | | .TXT information files | | .RAW ASCII data files (Level 1A) | | .LOG Processing log files (Level 2) | Processing (DSN) TNF's are screened for 'bad' data points by the JPL Radio Metric Data Conditioning Team (RMDCT) before the files are processed to ODF's. The TNF's included in this archive, however, are the prescreened versions. The open-loop (RSR) data in the archive have been assembled from individual records (packets) into files. They have not otherwise been processed. The Level 2 radio occultation data have been processed as follows: The RSR samples were digitally filtered to reduce bandwidth; in the process they were also converted from 16-bit I and 16-bit Q complex integer samples to 64-bit I and 64-bit Q double precision complex floating point samples. The complex floating point samples were Fourier transformed and estimates made of the carrier amplitude and frequency and their uncer- tainties. The reconstructed spacecraft trajectory, planetary epheme- redes, records of uplink and downlink tuning, and other data were used to calculate the expected carrier frequency at the receiving antenna. The Level 2 products are tables of the observed amplitude, its uncertainty, the observed frequency, its uncertainty, and the difference between the observed and the expected frequency as a function of time. Separate tables have been created for each RSR. The Level 2 bistatic radar spectra (SPC) have been processed as follows: The RSR samples were converted from 16-bit I and 16-bit Q complex integer samples to 64-bit I and 64-bit Q double precision complex floating point samples. In the process they were digitally corrected for non-uniform spectral response of the receiving system. This was done by computing spectra from series of time samples and dividing each spectrum by the square root of a power spectrum computed from many minutes of noise. The amplitude of the samples was then adjusted so that power spectra in each receiver channel would have an amplitude proportional to kTsysB where k is Boltzmann's constant, Tsys is the receiver system temperature in Kelvin, and B is the width of one frequency bin (spectral resolution) in the power spectrum. Then the power spectra (e.g., XR*conj(XR)) and cross spectra (e.g., XR*conj(XL)) were computed. Structure of DATA Directory = Please note that the following description lists all possible subfolders. If however there is no data to fill some of these folders they will not be generated. |-DATA | |-LEVEL1A | | |-CLOSED_LOOP | | | |-DSN | | | | |-ODF Orbit Data Files | | | | |-Tracking and Navigation Files | | | | | | | |-IFMS | | | |-AG1 Auto Gain Control 1 data files | | | |-AG2 Auto Gain Control 2 data files | | | |-DP1 Doppler 1 data files | | | |-DP2 Doppler 2 data files | | | |-RNG Ranging data files | | | | | |-OPEN_LOOP | | | |-DSN | | | | |-RSR Radio-Science Receiver data files | | | | | | |-IFMS | | |-AG1 Auto Gain Control 1 data files | | |-AG2 Auto Gain Control 2 data files | | |-DP1 Doppler 1 data files | | |-DP2 Doppler 2 data files | | |-RNG Ranging data files | | | |-LEVEL1B | | |-CLOSED_LOOP | | | |-DSN | | | | |-ODF Orbit Data Files | | | | | | | |- IFMS | | | | |- AG1 Auto Gain Control 1 data files | | | | |- AG2 Auto Gain Control 2 data files | | | | |- DP1 Doppler 1 data files | | | | |- DP2 Doppler 2 data files | | | | |- RNG Ranging data files | | | | | |- OPEN_LOOP | | | |-IFMS | | | | |-AG1 Auto Gain Control 1 data files | | | | |-AG2 Auto Gain Control 2 data files | | | | |-DP1 Doppler 1 data files | | | | |-DP2 Doppler 2 data files | | | | |-RNG Ranging data files | | | |-LEVEL2 | | |- CLOSED_LOOP | | | |- DSN | | | | |-ODF Orbit Data Files | | | | | | | |- IFMS | | | | |-DP1 Doppler 1 data files | | | | |-DP2 Doppler 2 data files | | | | |-RNG Ranging data files | | | | | |- OPEN_LOOP | | | |-DSN | | | | |-BSR Bistatic radar power spectra | | | | |-SRG Bistatic radar surface reflection | | | | | geometry file | | | | |-DPX Doppler X-Band files | | | | |-DPS Doppler S-Band files | | | | | | | |-IFMS | | | | |-DP1 Doppler 1 data files | | | | |-DP2 Doppler 2 data files | | | | |-RNG Ranging data files Files in the DATA Directory --------------------------- Files in the DATA directory are: Data Level 1A: -------------- Level 1A data are incoming raw tracking data files obtained either from ESA IFMS or DSN. All incoming data files will be renamed after the file naming convention format defined in section 5.1 of the VeRA File Naming Convention document [VRAFNC2005] and get a minimal detached label file .LBL. The original file name of the incoming tracking data files will be stored in the according label file as SOURCE_PRODUCT_ID. These files have the file extension .RAW if ASCII and .DAT if binary files. TNF's are screened for 'bad' data points by the JPL Radio Metric Data Conditioning Team (RMDCT) before the files are processed to ODF's. The TNF's included in this archive, however, are the prescreened versions. Tracking and Navigation Files (TNF Directory) --------------------------------------------- TNF's became available within a few hours of the completion of a Venus Express pass. Orbit Data Files ---------------- ODF's were typically issued daily throughout the VEX mission with weekend data being consolidated into a single file on Monday. Typical ODF's have sizes 15-50 kB. Sample rates typically are 1/sec or 1/(60 sec). Radio Science Receiver Files (RSR Directory) -------------------------------------------- Each RSR generated a stream of packets which could be assembled into files of arbitrary length. It was decided, after some experimentation, that files containing about 300 MB were the largest that could be easily manipulated in the analysis computers available in 2003. With a small number of exceptions, this is the largest file size that will be found in the RSR directory. The open-loop (RSR) data in the archive have been assembled from individual records (packets) into files. They have not other- wise been processed. IFMS Data Level 1B: ------------------- Level 1B files are created from level 1A (raw tracking data) as edited ASCII formatted file. Three files are generated for each ESA IFMS Level 1A data file: Level 1B IFMS data file (extension .TAB) Level 1B IFMS configuration file (extension .CFG) Level 1B IFMS label file (extension .LBL) The label file contains the description of the .TAB as well as of the .CFG file. Up to eight files are generated for each DSN ODF Level 1A file: Level 1B ODF Doppler S-Band data file + label file Level 1B ODF Doppler X-Band data file + label file Level 1B ODF Ranging S-Band data file + label file Level 1B ODF Ranging X-Band data file + label file Cologne is processing IFMS and ODF data, Stanford University processes RSR data up to level 2 and forwards raw and processed data to Cologne for archiving. However, for RSR there will be no level 1B files. Data Level 2: ------------- Level 2 data are calibrated data after further processing. The file format is in ASCII. This data level can be used for further scientific interpretation. The keyword OBSERVATION_TYPE in the Level 2 data labels indicates which kind of measurement was done. Keyword values are: Occultation, Target Gravity, Solar Conjunction, Bistatic Radar, Commissioning. Commissioning measurements were carried out on several days during the cruise phase and after Venus Express orbit insertion. These are measurements where the equipment on board the spacecraft and on the ground station was tested, as well as the different confi- gurations for the different kinds of measurements. IFMS Level 2 input files: ------------------------- There may be several Doppler 1 X-Band files in level 1A which will be merged on level 2. The same is true for all other Doppler file type and Ranging X and S-Band files. Only files with continuous sequenced numbers (the file names are the same only the sequence number varies for these files) are merged together. Otherwise a new Level 02 data file is created (merging data files with a new sequence of files). The level 2 source_product_id however gives the RAW IFMS file names since the raw files are used for processing. But the content of the IFMS raw files are identical to the corresponding level 1A IFMS files in one data set, only the file name is different. And the source_product_id of the level 1A files gives the original raw IFMS files. In addition the level 1A files have almost the same file name as the corresponding level 2 files. The corresponding level 1A files can be found in DATA/LEVEL1A/CLOSED_LOOP/IFMS/DP1 for Doppler 1 files DATA/LEVEL1A/CLOSED_LOOP/IFMS/DP2 for Doppler 2 files DATA/LEVEL1A/CLOSED_LOOP/IFMS/RNG for Ranging files ---------------------------------------------------------Example: V32ICL1L02_D1X_053450236_00.TAB is a level 2 Doppler 1 X-Band file in V32ICL1L02_D1X_053450236_00.LBL the following SOURCE_PRODUCT_ID is given: SOURCE_PRODUCT_ID = {NN11_VEX1_2005_345_OP_D1_023612_0000, NN11_VEX1_2005_345_OP_D1_023612_0001, NN11_VEX1_2005_345_OP_D1_023612_0002} which are the raw IFMS files. The corresponding Level 1A files can be found in DATA/LEVEL1A/CLOSED_LOOP/IFMS/DP1 Their names are: V32ICL1L1A_D1X_053450236_00.RAW V32ICL1L1A_D1X_053450236_01.RAW V32ICL1L1A_D1X_053450236_02.RAW and the corresponding label files give the source_product_id as: in the V32ICL1L1A_D1X_053450236_00.LBL file the source_product_id is given as: SOURCE_PRODUCT_ID = NN11_VEX1_2005_345_OP_D1_023612_0000 in the V32ICL1L1A_D1X_053450236_01.LBL file the source_product_id is given as: SOURCE_PRODUCT_ID = NN11_VEX1_2005_345_OP_D1_023612_0001 in the V32ICL1L1A_D1X_053450236_02.LBL file the source_product_id is given as: SOURCE_PRODUCT_ID = NN11_VEX1_2005_345_OP_D1_023612_0002 Note that in this example the three level 1A files were merged to one level 2 files. The file names of the level 1A files are almost identical to the level 2 file name with three differences: - L1A instead of L02 in the file name which tells the user that these are level 1A and level 2 files. - The two digit-sequence number at the end of the file can be different. - The level 1A files have file extension .RAW whereas level 2 files have file extension .TAB ---------------------------------------------------------Other inputs for Doppler and Ranging files: ------------------------------------------- predicted orbit file (see EXTRAS/ANCILLARY/UNI_BW) Meteorological file (see CALIB/CLOSED_LOOP/IFMS/MET) AGC file (see DATA/1A or 1B/CLOSED_LOOP/AGC1 or AGC2) Spacecraft orbit SPICE kernels (see EXTRAS/ANCILLARY/SPICE can also be downloaded from ftp://ssols01.esac.esa.int/pub/data/SPICE/VEX/kernels) Calibration Documentation: -------------------------- For documentation about Doppler and Ranging Calibration please see in DOCUMENT/VRA_DOC/VEX-VRA-IGM-DS-3011 and VEX-VRA-IGM-DS-3012. For differential Doppler: ------------------------- If the processed level 2 file is for example Doppler 1 X-Band then information from IFMS raw Doppler 1 S-Band files which cover approximately the same time were used for processing as well. For Doppler 1 S-Band information from IFMS raw Doppler 1 X-Band files were used. Doppler 2 files were processed accordingly. In most cases on IFMS1 and IFMS2 X-Band data were recorded: The corresponding raw files' names start with NN11_ or NN12_. S-Band data were in most cases recorded at IFMS3. The corresponding raw files' names start with NN13_. If for some reason this configuration was changed this is indicated either at the beginning of this description or at the end in the anomaly report. For Ranging in addition are used: --------------------------------- Range calibration file (see CALIB/CLOSED_LOOP/IFMS/RCL) Klobuchar coefficients for Earth-Ionosphere calibration (can be downloaded from this site: http://www.aiub.unibe.ch/download/CODE/) The calibrated Doppler files contain observed IFMS sky frequency, X-band Doppler and S-band Doppler frequency shift, residual (computed using the predict file), and the differential Doppler. If only a single downlink frequency was used, a differen- tial Doppler cannot be computed and was set to -999.999999 in the output file. The level 2 ranging files contain the observed TWLT at X-band or S-band, the calibrated TWLT at X-band or S-band, the TWLT delay at X-band or S-band and the differential TWLT. If only one frequency was used, the differential TWLT is set to -99999.9. IFMS Level 2 output files: -------------------------- Level 2 IFMS data file (extension .TAB) Level 2 IFMS label file (extension .LBL) Level 2 IFMS log file (extension .LOG). The log files can be found in /EXTRAS/ANCILLARY/VRA/LOGFILES and contain information about the level 2 Doppler and Ranging data processing. ODF Level 2 input files: ------------------------ ODF Level 1B files Doppler and Range prediction file or Orbit reconstructed file Media calibration files The calibrated Doppler files contain observed IFMS Doppler expressed as X-band Doppler or S-band Doppler, residual and detrended X-band or S-band Doppler (computed using the predict file), the detrended differential Doppler. If only one single frequency was used, the differential Doppler will be set to -999.999999. The level 2 ranging file contains the observed Two-Way- Light-Time (TWLT) at X-band or S-band, the calibrated TWLT at X-band or S-band, the TWLT delay at X-band or S-band and the differential TWLT. If only one frequency was used, the differential TWLT is set to -99999.9. Other inputs for Doppler and Ranging files: ------------------------------------------- Predicted orbit file (see EXTRAS/ANCILLARY/UNI_BW) Meteorological file (see CALIB/CLOSED_LOOP/ODF/MET) Spacecraft orbit SPICE kernels (see EXTRAS/ANCILLARY/SPICE can also be downloaded from: ftp://ssols01.esac.esa.int/pub/data/SPICE/VEX/kernels) RSR Level 2 data: ----------------- There are four types of 'calibrated' data in the data set; each is described briefly below. Surface Reflection Filter Files ------------------------------- SRF files contain power spectra derived from noise measure- ments when the radio system was stable and there were no spacecraft signals in the passband. SRF's were derived sepa- rately for each receiver channel; but the fact that the spectral characteristics of each receiver depended almost entirely on digital signal processing meant that there was little practical difference among channels when sampling rates (output bandwidths) were the same and the SRF's were interchangeable. SRF's were ASCII PDS SPECTRUM objects with attached labels. Level 2 Neutral Atmosphere Files -------------------------------- L2N files were the calibrated output of partial processing of RSR data collected for radio occultations. They were ASCII tables of frequencies and amplitudes in physically meaningful units. Separate L2N files were derived for each receiver channel. The Level 2 radio occultation data have been processed as follows: The RSR samples were digitally filtered to reduce bandwidth; in the process they were also converted from 16-bit I and 16-bit Q complex integer samples to 64-bit I and 64-bit Q double precision complex floating point samples. The complex floating point samples were Fourier transformed and estimates made of the carrier amplitude and frequency and their uncertainties. The reconstructed spacecraft trajectory, planetary epheme- redes, records of uplink and downlink tuning, and other data were used to calculate the expected carrier frequency at the receiving antenna. The Level 2 products are tables of the observed amplitude, its uncertainty, the observed frequency, its uncertainty, and the difference between the observed and the expected frequency as a function of time. Separate tables have been created for each RSR. Bistatic Radar Spectra ------------------------------ SPC files were the calibrated output of partial processing of RSR data collected for bistatic radar. They were ASCII tables of power and cross-voltage spectra. All spectra for a single observation were collected in a single ASCII file. The Level 2 bistatic radar spectra (BSR) have been processed as follows: The RSR samples were converted from 16-bit I and 16-bit Q complex integer samples to 64-bit I and 64-bit Q double precision complex floating point samples. In the process they were digitally corrected for non-uniform spectral response of the receiving system. This was done by computing spectra from series of time samples and dividing each spectrum by the square root of a power spectrum computed from many minutes of noise. The amplitude of the samples was then adjusted so that power spectra in each receiver channel would have an amplitude proportional to kTsysB where k is Boltzmann's constant, Tsys is the receiver system temperature in Kelvin, and B is the width of one frequency bin (spectral resolution) in the power spectrum. Then the power spectra (e.g., XR*conj(XR)) and cross spectra (e.g., XR*conj(XL)) were computed. Structure of CALIB Directory Please note that the following description lists all possible subfolders. If however there is no data to fill some of these folders they will not be generated. |-CALIB | |-CALINFO.TXT text description of the directory contents | | | |-CLOSED_LOOP | | |-DSN Closed-loop calibration data of the DSN ground | | | stations | | |-IFMS | | | |-RCL Range Calibration data files | | | |-DCL Doppler Calibration data files | | | |-MET Meteo data files | | | |-OPEN_LOOP | | |-DSN | | | |-BCAL System temperature calibration files | | | |-ION Ionospheric Calibration files | | | |-MET Meteo data files | | | |-TRO Tropospheric Calibration files | | | |-SRF Surface Reflection Filter Files | | | | | |-IFMS | | | |-RCL Range Calibration data files | | | |-DCL Doppler Calibration data files | | | |-MET Meteo data files | | | |-UPLINK_FREQ_CORRECT Only present if the uplink frequency in one of the .RAW files was identified as wrong. The Folder includes files which indicate the wrong and corrected uplink frequency and their corresponding files. Files in the CALIB Directory ---------------------------- Files in the CALIB directory are: Calibration data files have in principle the same structure as normal data files. But they do not contain scientific data but rather reflect the behaviour of the system. These kind of data is typically recorded at New Norcia once for every tracking before the real measurement took place. For example: range calibration data contain the equipment propagation delay measurements before the tracking pass. Note: If the uplink frequency in one of the .RAW files was identified as wrong the folder UPLINK_FREQ_CORRECT will be generated. It tells the user which files were affected and where to find the corrected Level 2 data files. Closed loop IFMS Calib data level 1A: ------------------------------------- These Level 1A data are incoming raw tracking data files obtained from ESA IFMS. All incoming data files will be renamed after the file naming convention format defined in section 5.1 of the VeRa File Naming Convention document [VRAFNC2005] and get a minimal detached label file .LBL. The original file name of the incoming tracking data files will be stored in the according label file as SOURCE_PRODUCT_ID. These files have the file extension .RAW. Closed loop IFMS Calib data level 1B: ------------------------------------- IFMS Calib level 1B files are processed from level 1A (raw tracking data) into an edited ASCII formatted file. Three files are generated for each ESA IFMS Level 1A data file: Level 1B IFMS data file (extension .TAB) Level 1B IFMS configuration file (extension .CFG) Level 1B IFMS label file (extension .LBL) The label file contains the description of the .TAB as well as of the .CFG file. DSN METEO Files (MET directory) ------------------------------- DSN METEO files were produced by the Tracking System Analytic Calibration (TSAC) Group at JPL. Files give weather calibration information for DSN complexes. These are ASCII files of variable length records. Each record is delimited by an ASCII line-feed (ASCII 10). METEO files were typically released weekly and contain all weather data for the complex since 1 January. Each METEO file is accompanied by a PDS label. The files grow at the rate of approximately 90 kB per month. DSN Ionosphere Calibration Files (ION Directory) ------------------------------------------------ Ionosphere Calibration files were produced by the Tracking System Analytic Calibration (TSAC) Group at JPL. They docu- mented and predicted Earth ionospheric conditions. Global Ionosphere Map (GIM) software created daily maps from Global Positioning System (GPS) data. Each day, a final map was created for the UT day three days previously and a preliminary map was created for the UT day immediately before. Also created were predict maps a couple times a week by averaging recent 'normal' days. Then the software evaluated the maps at the spacecraft line-of-sight and fitted the results to a normalized polynomial versus time over each spacecraft pass. This was done for all three modes: final, preliminary, and predict. Then the software selected the best available cali- bration for each pass (in priority order final > preliminary > predict). An operator ran a plotting program to view all of the calibrations and overrode the default selections where desired. The mapping technique is described by [MANNUCCIETAL1998]. They are ASCII files of variable length records. Each record is delimited by an ASCII carriage-return line-feed pair (ASCII 13 followed by ASCII 10). ION files were usually released at one week intervals to cover a single month; only final files covering a full month are included in this archive. Each ION file is accompanied by a PDS minimal label. Typical file sizes are approximately 50 kB. Troposphere Calibration Files (TRO Directory) --------------------------------------------- Troposphere Calibration files were produced by the Tracking System Analytic Calibration (TSAC) Group at JPL. They docu- mented and predicted Earth tropospheric conditions and were based on measurements made using Global Positioning System (GPS) satellites. These are ASCII files of variable length records. Each record is delimited by an ASCII line-feed (ASCII 10). Surface Reflection Filter Files (SRF Directory) ----------------------------------------------- SRF files contain power spectra derived from noise measure- ments when the radio system was stable and there were no spacecraft signals in the passband. SRF's were derived sepa- rately for each receiver channel; but the fact that the spectral characteristics of each receiver depended almost entirely on digital signal processing meant that there was little practical difference among channels when sampling rates (output bandwidths) were the same and the SRF's were inter- changeable. SRF's were ASCII PDS SPECTRUM objects with attached labels. System Temperature Calibration Files (BCAL directory) ----------------------------------------------------- This table contains system temperature calibration results from Venus Express (VEX) bistatic radar experiments. For each receiver channel the table includes the best estimate of system temperature with the antenna pointed to zenith (either pre- or post-cal, or a combination of both), the associated noise diode temperature, and the system temperature at the mid-point of the bistatic (surface) observation. In general there is one set of four rows for each experiment one for each receiver channel (X-band and S-band, right- and left-circular polarization). The table is cumulative, growing by four rows for each new observation. The Bistatic Radar Calibration Log is produced by the Stanford University Element (SUE) of the Venus Express Radio Science Team under the direction of R.A. Simpson. Browse Files (BROWSE Directory) = Browse files may be composite PostScript files summarizing quick-look processing of raw RSR data. In that case each file has a name: rggttttL1A_BRO_yydddhhmm_00.AUX. Each file has a JPEG version with the same file name but extension .LBL. Both files are accompanied by a single detached label of the same file name but extension .LBL. Each PostScript file is sized to fit on a single 8-1/2x11 inch page. Each landscape format page includes four panels showing a histogram of raw data (12-bit) samples (upper left), one-minute average power spectra derived from the raw samples (upper right), one-second averages of raw sample power versus time (lower left), and an extract of the first few lines of the source RSR PDS label (lower right). BRO files may be helpful in quickly scanning data to determine which files are suitable for closer study. IFMS Browse plot files are only available as JPEG files. These plots are generated in order to check data quality of IFMS Level 2 closed-loop data. The name of the files are the same like the Level 2 data files except for the data type identifier which is set as sss=B1X,B1S,B2X,B2S if the source of the plots is a Doppler 1 X-Band, Doppler 1 S-Band, Doppler 2 X-Band or Doppler 2 S-Band file, and the extension will be .JPG. Geometry information - Coordinate System The geometry items SC_SUN_POSITION_VECTOR, SC_TARGET_POSITION_ VECTOR and SC_TARGET_VELOCITY_VECTOR provided in the label of the data products are calculated from the spacecraft to the sun center expressed in J2000 reference frame, corrected for light time and stellar abberation. SUB_SPACECRAFT_LATITUDE, SUB_SPACECRAFT_LONGITUDE are given in the PLANETOCENTRIC coordinate system. These parameters are computed for the time given in POSITION_TIME. Distances are given in km, angles in degrees. More information can be found in the geometry_index file under INDEX/. Documentation is available in the VRA document folder. Ancillary Data An extensive set of ancillary files is needed for proper analysis and interpretation of the radio data. These are organized in parallel directories and stored approximately chronologically. When a file type is not represented on a volume, the corresponding directory has been omitted. Files in the EXTRAS/ANCILLARY Directory --------------------------------------- Files in the EXTRAS/ANCILLARY directory are: ESOC: R^ant DDS files to describe the observation geometry SPICE: R^ant SPICE Kernels to describe the observation geo- metry UNI_BW: R^ant PREDICT files from the Uni BW Munich VRA: Level 2 processing log files SUE: Ancillary files coming from Stanford University |-SPICE: Spice Kernels were produced by the VEX Flight Dynamics Team, converted to IEEE binary format, and then distri- buted by the JPL Navigation and Ancillary Information Facility (NAIF). For more information on NAIF and SPICE see http://pds-naif.jpl.nasa.gov/ The original Spice Kernels were merged with the JPL DE405 planetary ephemeris and the ephemeredes of Phobos and Deimos for the same time interval. DSN: Ancillary files provided by Deep Space Network |-EOP: Earth Orientation Parameter Files | Earth Orientation Parameter files were produced by the | Time and Earth Motion Precision Observation (TEMPO) | Group at JPL. They documented and predicted Earth rota- | tion (rate and axis). These are ASCII files of variable | length records. Each record is delimited by an ASCII | line-feed (ASCII 10). | There are both 'long' and 'short' versions. The long | file covered past motion since about 1962 and a predic- | tion for about three months into the future; these files | have typical sizes of 1 MB. | The short file covered the most recent nine months of | past motion and a prediction for three months into the | future; these files are typically 30 kB. Each EOP file | is accompanied by a PDS minimal label. | |-OPT: Orbit Propagation and Timing Geometry File | Orbit Propagation and Time Generation files contain | estimates of event timing (e.g., equator crossings) that | depend on precise knowledge of the spacecraft orbit. | These are ASCII files of variable length records. Each | record is delimited by an ASCII carriage-return | (ASCII 13) line-feed (ASCII 10) pair. File names | have the form ydddeeeC.OPT where the file name compo- | nents are the same as for BCK files (above). | Each OPT file is accompanied by a PDS minimal label with | file name ydddeeeC.LBL. Typical files are based on | reconstructed spacecraft trajectories, cover a month of | operation, and have sizes less than 500 kB. | |-LIT: Light Time File | Light Time files give radio propagation time from the | spacecraft to Earth as a function of time. These are | ASCII files of fixed length records. Each record is | delimited by an ASCII carriage-return line-feed pair. | File names have the form ydddeeeC.LIT where the file | name components are the same as for DKF files. An LIT | file may cover more than 365 days; so eee may be a year | or more after yddd. Each LIT file is accompanied by a | PDS label. Typical file sizes are less than 1 MB. Software Software for parsing, reducing, and analyzing data such as these has been developed at University of Cologne and Stanford University. Because such software must usually operate at the bit-level and is written for a narrow range of platforms, it is not suitable for general distribution. No software is included with this archival data set. Documents = The DOCUMENT directory contains the files that provide documen- tation and supplementary information to assist in understanding and using the data products on the volume. The files evolved as the mission progressed; users should refer to the files on the most recent (highest numbered) archive volume for the most up-to-date information. Files on early volumes may be only 'place-holders'. The below mentioned documents represent the maximum of available documents, but need not to be present for every measurement. For IFMS (NNO) measurements, please refer mainly to VRA_DOC, for DSN measure- ments to DSN_DOC. Structure of the DOCUMENT directory: DOCUMENT | |- DOCINFO.TXT The file you are reading. |- VEX_POINTING_MODE_DESC.TXT VEX pointing mode | description |- OBSERVATION_TYPE_DESC.TXT VEX Observation types | |- VRA_DOC | | | |- M32ESOCL1B_RCL_021202_00.PDF Group delay stability | | .ASC specification and | | measurements at New Norcia. | | | |- M32ESOCL1B_RCL_030522_00.PDF Range calibrations at New | | .ASC Norcia and Kourou. | | | |- M32UNBWL1B_RCL_030801_00.PDF Transponder group veloci- | | .ASC ties (in German, .ASC in | | English). | | | |- VEX.VRA-IGM-IS-3007.PDF VeRa Data Archive Plan. | | VEX-VRA-IGM-IS-3007.ASC | | | |- VEX-VRA-IGM-IS-3009.PDF VRA File Naming Convention | | VEX-VRA-IGM-IS-3009.ASC | | | |- VEX-VRA-IGM-MA-3005.PDF VRA User Manual. | | | |- VEX_OPS_LOGBOOK_06.PDF Status of all planned | | radio science operations | | in year 2006 (later 07,08) | | | |- VEX-VRA-IGM-LI-3013.PDF List of VRA Team members. | | | |- VEX_VRA_IGM_DS_3011.PDF IFMS Doppler Processing and | | Calibration Software | | Documentation: Level 1A to | | Level 2. | | | |- VEX_VRA_IGM_DS_3012.PDF IFMS Ranging Processing and | | Calibration Software | | Documentation: Level 1A to | | Level 2. | | | |- VEX-VRA-IGM-DS-3014.PDF Radio Science Predicted | | and Reconstructed Orbit and | | Planetary Constellation | | Data: Specifications | | | |- VEX-VRA-UBW-TN-3040.PDF Reference Systems and Tech| | niques for Simulation and | | Prediction of atmospheric | | and ionospheric sounding | | measurements | | | |- VEX-VRA-IGM-DS-5007.PDF Radio Science Geometry and | | Position Index Software | | Design Specifications | | | |- VEX-VRA-IGM-DS-5008.PDF ODF Processing and Calibra| | tion Software: Level 1a to | | Level 1b Software Design | | Specifications | | | |- VEX-VRA-IGM-DS-5009.PDF ODF Doppler Processing and | | Calibration Software: Level | | 1b to Level 2 Software | | Design Specifications | | | |- VEX-VRA-IGM-DS-5010.PDF ODF Ranging Processing and | Calibration Software: Level | 1b to Level 2 Software | Design Specifications | |- ESA_DOC | | | |- IFMS-OCCFTP.PDF Documentation of IFMS data | | format. | | | |- VEX_ARCHIVE_CONVENTIONS.PDF Archive Conventions | | | | | |- VEX-ESC-IF-5003.PDF Data delivery interface | | document. | | | |- VEX-ESC-ID-5003_FDSICD.PDF File format description of | | ESOC Flight Dynamics files | | (ancillary files). | | | |- VEX-ESC-IF-5003_APPENDIX_C.PDF Documentation of DDS confi| | guration. | | | |- VEX-ESC-IF-5003_APPENDIX_I.PDF Definition of XML-schema | | for the data delivery | | interface. | | | |- VEX-ESC-IF-5003_APPENDIX_H.PDF Description of content of | | ESOC Flight Dynamics files | | (ancillary files). | | | |- VEX-RSSD-IF-0002.PDF Specifications of operatio| | nal interfaces and proce- | | dures | | | |- SOP-RSSD-TN-010.PDF Planetary Science Data | | Archive Technical Note Geo| | metry and Position Informa| | tion | | | |- VEX_ORIENTATION_DESC.TXT VEX Orientation description | | | |- VEX_POINTING_MODE_DESC.TXT VEX pointing mode descrip- | | tion | | | |- VEX_SCIENCE_CASE_ID_DESC.TXT VEX description of the | | science cases | | | |- VEX-RSSD-LI-009.TAB VEX Mission subphases | | | |- OBSERVATION_TYPE_DESC.TXT VEX Observation types | | | |- VEX_MISSION_CALENDAR.PDF Description of the | | different phases of the | | mission. | | | | | |- VEX-EST-TN-036.PDF VEX Archive Conventions | | |- DSN_DOC | | | |-DSN_DESIGN_HB.PDF/.ASC | | Technical information and near future configurations of | | NASA Deep Space Network | | | |-DSN_ODF_TRK-2-18.PDF | | Documentation of Tracking System Interfaces and Orbit Data | | File Interface | | | |-JPL_D-16765_RSR.PDF | | Documentation of RSR data format | | | |-LIT_SIS.HTM | | Software Interface Specification: Light Time File | | | |-V00DSN0L1A_DKF_yydddhhmm_vv.TXT (optional) | | DSN Keyword File derived from SOE file and models of | | activities supported by the DSN | | | |-V00DSN0L1A_SOE_yydddhhmm_vv.TXT (optional) | | Sequence of Events file | | | |-VggDSN0L1A_NMC__yydddhhmm_vv.TXT (optional) | | Network Monitor and Control Logfile | | | |-V43SUE0L1A_MFT__yydddhhmm_vv.TXT (optional) | | Venus Express Manifest file | | | |-MEDIASIS.HTM | | Media Calibration data: formats and contents | | | |-MON0158.ASC/.DOC/.PDF (optional) | | Definition of format and distribution of the real-time, | | mission monitor data | | | |-NMC_SIS.TXT | | Contents of Network Monitor and Control Log. | | | |-OPTG_SIS.TXT | | Software Interface Specification for the Orbit Propagation | | and Timing Geometry (OPTG) file. | | | |-Ryddd.ASC/.DOC/.PDF (optional) | | Set of notes describing tests before and during radio | | science tests or operations or the progress of an | | experiment itself. y represents the year, ddd the DOY. | | | |-JPEG | | Zip-folder with 4 sets of 24 jpeg-files, each from a | | different receiver, showing circularly polarized received | | power spectra averaged over 60 seconds. FILENAME: | | Rydddbca.jpg with y:year, ddd:doy, b:X- or S-band, c: Left | | or Right-Hand circulation, a:alphabetic numbering for each | | plot of 60s. | | | |-SRX.TXT (optional) | | Software Interface Specification for Surface Reflection | | investigation files. | | | |-TNF_SIS.TXT | | Deep Space Mission System External Interface Specification | | | |-TRK_2_21.TXT | | Software Interface Specification | | | |-TRK_2_23.TXT / DSN_MEDIA_CAL_TRK_2_23.PDF | | Specification of DSN media calibration data. | | | |-TRK_2_24.TXT / DSN_WEA_FORMAT_TRK_2_24.PDF | | Specification of DSN weather file. The documents are either in PDF-Format or are text files in ASCII with variable length of characters per line. Each line is delimited with a carriage-return (ASCII 13) line-feed (ASCII 10) pair. Media/Format The archival data set is written on CD-WO media using the WinOn CD Creation Software or Nero Burning Rom. The CD-WO volumes conform to ISO 9660 standards. More general description of radio science data Closed-loop and Open-loop data: There are in principle two different ways to record radio science data: Open-loop and closed-loop data. The CLOSED-LOOP system used a phase-lock loop in the receiver to track the downlink signal, reporting both amplitude and fre- quency at rates typically of 1-10 times per second. In the OPEN-LOOP system, the signal was simply converted to a baseband frequency range; the entire passband was sampled and recorded for later processing. Typical open-loop sampling rates for VEX were 100000 complex samples per second. CLOSED-LOOP data are efficient for characterizing slowly changing signals; OPEN-LOOP data (because of their much higher volume) are usually used when the signal is very dynamic - such as during an occultation or bistatic radar measurement. The data set includes four primary data types with respect to the two different ground station systems. These systems are on the one hand the ESA ground station in New Norcia, Australia (NNO) and the NASA Deep Space Network (DSN). CLOSED-LOOP data types: | |- ESA: Intermediate Frequency Modulation System (IFMS) | Closed-Loop (CL) | | In this data set file names of data recorded at the | New Norcia IFMS closed loop system start with the | string 'V32_ICL' for Level 2. | | IFMS CL consists of Doppler and Ranging data at | selected sample rates. The sample rate is usually | 1/s. | The only exception are occultation data where the | sample rate should be 10/s to get a good enough | vertical resolution of the atmosphere. | Ranging are only recorded for gravity measurements. | | Thus the IFMS closed loop has three recording | systems IFMS 1, IFMS 2 and IFMS 3 | The standard_data_product_id in the data label | specifies on which system the data was recorded. | | VeRa measurements are usually done in TWO-WAY | configuration: that is an uplink signal goes up | (this is usually X-Band but the uplink signal can | also be S-Band) and the ground station receives a | dual frequency simultaneous and coherent downlink | signal. | | IFMS 1 is configured for the uplink signal. It | receives X-Band downlink if uplink was X-Band and | S-Band downlink if uplink was S-Band. | IFMS 2 acts as backup. | IFMS 3 records the second downlink signal. This is | usually S-Band. But can also be X-Band when the | uplink was S-Band. | | IFMS 1 D1 is fixed to a sample rate of 1/s | IFMS 1 D2 is on fixed to a sample rate of 1/10s | | In addition each Doppler recording system has also | two Doppler channels which can record simultaneous| ly and act as an additional backup system. | Therefore for each IFMS system there should be at a | given time two Doppler files and two Auto Gain | Control files recorded. The file names of these | data contain the string '_D1' or '_D2' for Doppler | and '_G1' or '_G2' for Auto Gain control files and | they will be on different subfolders within the | data directory. See further down the description of | the DATA Directory. | | For these data files only X-Band ranging was | possible. Ranging data was nominally recorded on | IFMS1. | |- DSN: |-Tracking and Navigation File (TNF) | | The Tracking and Navigation File (TNF) is the primary out| put from the DSN closed-loop receiver system. These are | large files, accumulating at the rate of approximately 3 | megabytes (MB) per hour of antenna operation. The files | comprise nearly 20 block types, each designed to carry | data of interest to a particular navigation, telecommuni- | cations, or science community. | The blocks are described by TNF_SIS.TXT in the | DOCUMENT/DSN_DOC directory. Fields include: | Uplink and downlink antenna numbers | Spacecraft number | Equipment identifiers, status flags, and calibration | values | Time tags and frequency bands | Transmitted and received phase and frequency | Transmitted and received ranging information | Noise levels, signal-to-noise ratios, and uncertain- | ties | |-Orbit Data Files (ODF) | | For many applications the TNF is too cumbersome. The ODF | is an edited and partially processed version of the TNF. | It is a smaller file, often issued in daily increments of | about 0.2 MB. It contains the most important information | (range and Doppler) needed by spacecraft navigators and | investigators interested in determining gravitational | fields of bodies such as Mars. | Each ODF is accompanied by a full PDS label which | describes both the content and format of the associated | file. ODF data fields include: | Narrowband spacecraft VLBI, Doppler mode (cycles) | Narrowband spacecraft VLBI, phase mode (cycles) | Narrowband quasar VLBI, Doppler mode (cycles) | Narrowband quasar VLBI, phase mode (cycles) | Wideband spacecraft VLBI (nanoseconds) | Wideband quasar VLBI (nanoseconds) | One-way Doppler (Hertz) | Two-way Doppler (Hertz) | Three-way Doppler (Hertz) | One-way total count phase (cycles) | Two-way total count phase (cycles) | Three-way total count phase (cycles) | PRA planetary operational discrete spectrum range (range | units) | SRA planetary operational discrete spectrum range (range | units) | RE(GSTDN) range (nanoseconds) | Azimuth angle (degrees) | Elevation angle (degrees) | Hour angle (degrees) | Declination angle (degrees) | | For more information please refer to document | [DSN_ODF_TRK-2-18] in the DOCUMENT/DSN_DOC folder. Open- Loop data types: | |-ESA: Intermediate Frequency Modulation System (IFMS) Open-Loop | (OL) | | In this data set file names of data recorded at the | New Norcia IFMS open loop system start with the | string 'V32_IOL' for Level 2. | | IFMS OL consists of Doppler data at selected | sample rates. The sample rate is usually | 100000 samples per second. | | The IFMS open loop has three recording systems | IFMS 1, IFMS 2 and IFMS 3, whereas the Doppler | channel 1 (D1) of the IFMS 2 and 3 (NN12 and NN13 | in the original filenames) receives open loop data. | The other channels are configured as described in | the closed loop section. | The standard_data_product_id in the data label | specifies on which system the data was recorded. | | VeRa open loop measurements are usually done in | ONE-WAY configuration: that is the spacecraft | sends and the ground station receives a dual | frequency simultaneous and coherent downlink | signal. IFMS 2 D1 receives usually X-band, IFMS 3 | D1 usually S-band. Sometimes the configuration was | such that both channels received X-band. | | Open-loop measurements come from the GDSP 17.5 Msps | 24-bit complex base band stream (containing 1, 2, | 4 or 12 bit words each for the I and Q channels) | and result from filtering and decimating the | 280 Msps 8-bit stream output by the Common Front | End (CFE) Analogue to Digital converter. These | channels are provided for both RHC and LHC | polarizations. | | The Open-Loop data-sets contain: | First data-set (sequence Id=0000): standard header | and active configuration in ASCII. | Following data-sets (sequence Id >=0001): fixed- | length binary records containing each a header (76 | bytes: record length, sampling frequency, samples | quantization, time stamp of first sample, LO Fre- | quency off-set of single channels, LO Frequency | sweep rate), and data (1392 bytes, 87 complex | samples); a new data-set is open every minute. | Each complex sample consists of 16 bits in phase | sample (real part) for each channel, and 16 bits | qudrature sample (imaginary part) for each channel. | There are four channels, but actually channel 1 and | 2 are used for Radio Science open-loop data. | | The binary open-loop datasets are formatted by the | IFMS and transported to the ESU (External Storage | Unit) via the IFMS Ethernet network ports. | | |-DSN: Radio Science Receiver (RSR) | | The Radio Science Receiver (RSR) is a computer- | controlled open loop receiver that digitally records a | spacecraft signal through the use of an analog to | digital converter (ADC) and up to four digital filter | sub-channels. The digital samples from each | sub-channel are stored to disk in one second records | in real time. In near real time the one second records | are partitioned and formatted into a sequence of RSR | Standard Format Data Units (SFDUs) which are | transmitted to the Advanced Multi-Mission Operations | System (AMMOS) at the Jet Propulsion Laboratory (JPL). | Included in each RSR SFDU are the ancillary data | necessary to reconstruct the signal represented by the | recorded data samples. | | Each SFDU is defined here as a single row in a | PDS TABLE object; later SFDUs are later rows. The | first fields in each row contain the ancillary data | (time tags and frequency estimates, for example) that | applied while the samples at the end of the record | were being collected. The object definitions below | explain where the fields are and what the contents | represent. | | Analysis of variations in the amplitude, frequency, | and phase of the recorded signals provides information | on the ring structure, atmospheric density, magnetic | field, and charged particle environment of planets | which occult the spacecraft. Variations in the | recorded signal can also be used for detection of | gravitational waves. | | DSN open-loop receivers sample a narrow part of the micro| wave spectrum near the spacecraft transmitting frequency. | For radio occultation tests, two RSR's were used - one | each for X-RCP and S-RCP with output sampled at rates of | 2000 (complex; 16-bit I, 16-bit Q). | The data were examined for compliance with data acquisi- | tion procedures and to measure the frequency/stability of | the radiolink. Four RSR's (X-RCP, S-RCP, X-LCP, and S-LCP) | each sample at a rate of 25000 (complex; 16-bit I, | 16-bit Q) to test bistatic radar data acquisition. | | Header information accompanying each RSR record included: | | Date and time of the first data sample | Sample rate and channel assignments | Receiver local oscillator phase and frequency | Attenuator settings | RMS voltages at several stages in the receiving chain | | | For more information please refer to document | [JPL_D-16765_RSR] in the DOCUMENT/DSN_DOC folder.
Instrument VRA
Temporal Coverage 2012-06-30T00:00:00Z/2012-06-30T00:00:00Z
Version V1.0
Mission Description Mission Overview Venus Express is ESA's first mission to Venus. It reuses the design of the Mars Express spacecraft. Many of the instruments are simply upgraded versions of those developed for ESA's Mars Express and Rosetta missions. The scientific objectives of the mission is to study the atmosphere, the plasma environment, and the surface of Venus in great detail. Venus Express was launched by a Soyuz-Fregat launcher from the Baikonour Cosmodrome on 9 November 2005. After separation, Venus Express, of mass 1244 kg,was placed into an interplanetary transfer orbit during approximately 150 days. After a 153 day cruise to Venus the spacecraft entered Venusian orbit on 11 april 2006. The first capture orbit was an eccentric polar and lasted 9 days. Several manoeuvres over the period 15 April-6 May 2006 lowered the spacecraft into its operational orbit: a 24-hour elliptical, quasi-polar orbit. The pericentre altitude is 250 kms and the apocentre altitude is 66000 kms. Pericentre altitude 250 km Apocentre altitude 66000 km Period 24 h Inclination ~90 deg Pericentre latitude 80 deg The mission has been described in many papers [ESA2005; HUNTER2004]. Details about the mission launch sequence and timeline can be obtained from the Mission Calendar [DAUVIN2005] and from the Consolidated Report on Mission Analysis (CREMA) [SANCHEZ&RODRIGU2005]. Mission Phases The mission timeline defines the different spacecraft and payload operations required per phase to prepare the spacecraft for Venus operational orbit acquisition, science data acquisition and transmission. The pre-routine mission phase, which are: - the pre-launch phase - the launch and early orbit phase - the near earth commissioning phase - the interplanetary cruise phase - the venus orbit insertion phase - the venus orbit commissioning phase, the nominal mission phase and the extended mission phases phase are detailed below. PRELAUNCH ---...------ Pre-launch operations started approximately 6 months before the launch and covered the period from delivery of the spacecraft to the launch site until L-8 hrs in the launch countdown sequence. During this period the Venus Express Mission Operations Centre (VMOC) at ESOC performed its final simulation programme including the validation of the Flight Operations Plan (FOP) and the final mission control system. mission phase start time : ~ June 2005 mission phase stop time : 2005-11-09 LAUNCH AND EARLY ORBIT PHASE (LEOP) ----------------------------------- The Venus Express spacecraft was launched on a Soyouz-Fregat rocket from the Baikonur Cosmodrome at 3:33:34 UT on 9 November 2005. The three-stage Soyuz launcher lifted the Fregat autonomous upper stage (fourth stage) with Venus Express mounted on it into a sub-orbital trajectory. After separation from the Soyuz third stage, a Fregat main engine burn (at an altitude of about 200 kilometres) for around 20 seconds placed the Fregat-Venus Express composite into an almost circular parking orbit. After a coast phase of about 70 minutes in the low Earth orbit, a second Fregat engine burn, lasting 16 minutes, moved the combined craft from the parking orbit onto an escape trajectory, after which the Fregat stage and Venus Express separated. Duration : 3 days mission phase start time : 2005-11-09 mission phase stop time : 2005-11-11 After separation, Venus Express spent approximately 150 days in an interplanetary transfer orbit. During this phase, trajectory corrections were performed using the spacecraft's own thrusters. NEAR EARTH COMMISSIONING PHASE (NECP) ------------------------------------- It included the following activities for the spacecraft: - spacecraft commissioning. - deployment of the MAG Boom. - Payloads commissioning. Duration : 3 weeks mission phase start time : 2005-11-12 mission phase stop time : 2005-12-16 INTERPLANETARY CRUISE PHASE --------------------------- The Interplanetary Cruise Phase finished about one month before Venus capture. During this 3 months phase, the spacecraft was on the Sun-centred ballistic orbit to Venus. Most of this phase was not dedicated to any specific activity, except the cruise orbit determination and correction. Duration : 107 days mission phase start time : 2005-12-17 mission phase stop time : 2006-04-04 VENUS ORBIT INSERTION PHASE (VOI) --------------------------- The Venus Orbit Insertion (VOI) phase was the period of transition between the Interplanetary Cruise phase and the final operational orbit around Venus. It started before the Venus capture manoeuvre and ended when the satellite reached the operational orbit. The duration of this phase was about 2 weeks. A final course adjustment was performed on 29 March to fine tune the arrival hyperbola for Venus Orbit Insertion. The VOI manoeuvre took place on 11 April 2006. To enable capture of the spacecraft, it was first slewed such that the main engine was aligned to the direction of travel. The main engine burn lasted around 50 minutes and decelerated the spacecraft by approximately 1251 ms-1 (~ 4500 kmh-1). The spacecraft initially entered a highly elliptical polar orbit with a pericentre of 400 km, an apocentre of 350 000 km and a period of 9 days. To achieve the final operational orbit a series of correction manoeuvres were necessary: Date Activity Velocity Change (m/s) 15 April 2006 Pericentre Control Manoeuvre #1 5.8 20 April 2006 Apocentre Lowering Manoeuvre #1 199.9 23 April 2006 Apocentre Lowering Manoeuvre #2 105.3 26 April 2006 Apocentre Lowering Manoeuvre #3 9.2 29 April 2006 Apocentre Lowering Manoeuvre #4 8.0 2 May 2006 Apocentre Trim 2.0 6 May 2006 Pericentre Control Manoeuvre #2 3.1 Duration : 16 days mission phase start time : 2006-04-05 venus capture manoeuvre : 2006-04-11 mission phase stop time : 2006-04-21 VENUS ORBIT COMMISSIONING PHASE --------------------------------- The Venus Payload Commissioning phase started when the spacecraft reached the operational orbit and ended when it was declared ready for science data acquisition and transmission to the Earth. It was dedicated to spacecraft commissioning activities, payloads commissioning and demonstration activities prior to operational science operations. The duration of the Payload Commissioning phase around Venus was about 1 month. The operations to be performed during the phase were the following: - S/C in-orbit commissioning, - Payloads in-orbit commissioning, - Isolation of the Propulsion system. Duration : 42 days mission phase start time : 2006-04-22 mission phase stop time : 2006-06-03 ROUTINE OPERATIONS PHASE ------------------------ The selected operational orbit was inertially fixed, so that coverage of all planetocentric longitudes was accomplished in one Venus sidereal day (243 Earth days). The nominal mission orbital lifetime was two Venus sidereal days (486 Earth days). It consisted in science data acquisition from the payloads, data storage in the SSMM and data transmission to the Earth. There were two different phases of operations for Venus Express once it was in operational orbit: the Earth Pointing phase and the Observation phase. The Earth pointing phase was dedicated to communication with Earth and battery charging. It was used whenever the spacecraft was not in the observation phase. In the Earth pointing phase, one of the two High Gain Antennas was oriented towards Earth. The antenna was selected according to the season, so that the spacecraft's cold face remained always protected from illumination by the Sun. The rotation angle around the Earth direction was optimised in order to avoid any entrance of Sun light on the side walls radiators. High rate communication was performed 8 hours per day in X-band, in order to transmit to Earth all science data stored in the Solid State Mass Memory. An average of 2 Gbits of science data was downlinked every day to the new ESA ground station of Cebreros, Spain. The observation phase consisted of several different modes of observation, depending on the payload configuration and spacecraft orientation: Nadir pointing, Limb observation, Star occultation, Radio science. During observation, the Sun could illuminate under transient conditions any spacecraft face, except for the cold face. The duration of observation was therefore limited by thermal constraints and by battery discharge. The maximum duration of an observation period depended on the Sun direction with respect to the orbit plane, which varied along the mission. Observations and spacecraft activities were planned based on the following principles: 1. Complete and uniform the coverage of the science themes 2. Balance between distant and close-up view of Venus 3. Balance between observations of the Northern and Southern hemisphere 4. Synergy between experiments in covering science objectives 5. Use of two cases in each orbit: one in apocentre, one in pericentre 6. Even distribution of pericentric cases with priority given to the solar and Earth radio occultation experiments in specific seasons 7. Apocentric cases (2,3) were grouped in campaigns of 10 orbits that was required by the atmospheric dynamics mission objectives 8. Maximum compliance with the current flight rules. Individual Objectives per Instrument ------------------------------------ ASPERA On during the entire mission and permanently collecting data. Survey observations in the beginning of the mission and more specific and detailed observations on selected part of the orbit later in the mission. Data was collected at different rates depending on the selected mode. MAG On during the entire mission and permanently collecting data. Data was collected at different rates depending on the selected mode. SPICAV The main goal of SPICAV was to sound the Venus atmosphere in solar and stellar occultation geometry with sufficient latitude and local time coverage. SPICAV did also nadir and corona observations (90 deg slew from nadir pointing and back to nadir). VeRa 4 types of observations 1. Earth occultation with as good as possible latitude and local time coverage of Venus. 2. Bi-static sounding of surface targets. The radio signal was sent to selected targets on the Venus surface. Reflected and scattered signal was received by ground station. As the signal was weak, the experiment depended on the Earth Venus distance, geometry and surface target properties. 3. Solar Corona observations in vincinity of conjunctions. 4. Gravity anomaly. It consisted in the precise tracking of the s/c while it passes over global geological formations on Venus solid body. It has been carried out only twice during the nominal mission . The Gravity Anomaly observations have been abandoned since the end of the nominal mission as the added scientific value with respect to previous observations was very small. Duration : 486 days mission phase start time : 2006-06-04 mission phase stop time : 2007-10-02 EXTENDED OPERATIONS PHASE ------------------------- The nominal mission ended on October 2, 2007 when started the first extended mission. The first extended mission phase was approved until May 2009, end of MTP 040, May 30th, orbit 1135. It was followed by the second mission extension from MTP 041 that started in May, 31 2009 (orbit 1136). The second extension was followed by the third extension that started with MTP 057, August 22nd 2010, orbit 1584. The third extension ended with MTP 085 in December 2012. The third extension was followed by the fourth extension that started with MTP 088, January 6th 2013, orbit 2452. Summary of extended mission phase --------------------------------- NOMINAL MISSION MTP 002 Day 4 June 2006 Orbit 44 EXTENSION 1 MTP 019 Day 3 October 2007 Orbit 530 EXTENSION 2 MTP 041 Day 31 May 2009 Orbit 1136 EXTENSION 3 MTP 057 Day 22 August 2010 Orbit 1584 EXTENSION 4 MTP 088 Day 6 January 2013 Orbit 2452 Note: To ease the grouping and delivery of products to the archive, the start date of the EXTENSION 4 data sets has been set to 1 January 2013. EXTENSION 1, 2, 3, 4: General Observation strategy ----------------------------------------------- The first extended mission had the following objectives: - Improve and complete spatial and temporal observational coverage - Study in detail the phenomena discovered in the nominal mission - Take advantage of the new operation modes (case #2 pendulum, spot pointing, ...) - Perform pericentre lowering down to the altitude that still allows usual operations without entering aerobraking mode (around 170-270 km) - Perform necessary studies and tests preparing the spacecraft for future aerobraking campaign These goals determined the following planning outline for the extended mission: - October 3, 2007 - May 31, 2008 (MTP 19-27): like nominal mission - June 2008 - TBD operations with low pericentre. - TBD: Aerobraking campaign. Pericentre lowering campaign: The pericentre altitude was maintained between 250 km and 350 km during the first 8 months of the extended mission. After May 31, 2008 the pericentre was lowered to the corridor 170-220 km. This pericentre lowering aimed at observing plasma at this altitude range. The apocentre and the pericentre latitude hasn't changed (66000 km, about 78 deg). Science Subphase ---------------- For the purpose of structuring further the payload operations planning, the mission phases were further divided into science subphases. Phase number Date Orbit CRUISE 2005-11-09 -1 VOI 2006-04-11 0 PHASE 0 2006-05-14 23 PHASE 1 2006-06-04 44 PHASE 2 2006-07-11 82 PHASE 3 2006-09-14 146 PHASE 4 2006-11-16 209 PHASE 5 2007-02-01 286 PHASE 6 2007-03-16 330 PHASE 7 2007-04-25 370 PHASE 8 2007-06-30 436 PHASE 9 2007-08-21 488 PHASE 10 2007-10-04 531 PHASE 11 2007-10-27 554 PHASE 12 2008-01-04 623 PHASE 13 2008-04-01 711 PHASE 14 2008-06-05 776 PHASE 15 2008-08-01 833 PHASE 16 2008-09-23 886 PHASE 17 2008-12-31 985 PHASE 18 2009-03-02 1046 PHASE 19 2009-05-05 1110 PHASE 20 2009-06-24 1160 PHASE 21 2009-09-20 1248 PHASE 22 2009-10-18 1276 PHASE 23 2009-12-17 1336 PHASE 24 2010-02-02 1383 PHASE 25 2010-04-07 1447 PHASE 26 2010-05-30 1500 PHASE 27 2010-07-12 1543 PHASE 28 2010-07-30 1561 PHASE 29 2010-09-14 1607 PHASE 30 2010-11-19 1672 PHASE 31 2011-01-17 1732 PHASE 32 2011-03-23 1797 PHASE 33 2011-04-26 1831 PHASE 34 2011-06-14 1880 PHASE 35 2011-08-27 1954 PHASE 36 2011-10-25 2013 PHASE 37 2011-12-05 2054 PHASE 38 2012-01-08 2088 MTP 76 2012-02-05 2116 MTP 77 2012-03-04 2144 MTP 78 2012-04-01 2172 MTP 79 2012-04-29 2200 MTP 80 2012-05-27 2228 MTP 81 2012-06-24 2256 MTP 82 2012-07-22 2284 MTP 83 2012-08-19 2312 MTP 84 2012-09-16 2340 MTP 85 2012-10-14 2368 MTP 86 2012-11-11 2396 MTP 87 2012-12-09 2424 MTP 88 2013-01-06 2452 MTP 89 2013-02-03 2480 MTP 90 2013-03-03 2508 MTP 91 2013-03-31 2536 MTP 92 2013-04-28 2564 MTP 93 2013-05-26 2592 MTP 94 2013-06-23 2620 MTP 95 2013-07-21 2648 MTP 96 2013-08-18 2676 MTP 97 2013-09-15 2704 MTP 98 2013-10-13 2732 MTP 99 2013-11-10 2760 MTP 100 2013-12-08 2788 MTP 101 2014-01-05 2816 MTP 102 2014-02-12 2844 Note: Science subphases defined after PHASE 38 include only one MTP. To ease the mapping between science subphases and MTPs, it was agreed to name these subphases following the convention: MTP nn. VOI and Phase 0 ------- This initial phase was devoted to the spacecraft and payload checkout and in orbit commissioning. The phase consisted of: - experiments commissioning (until 14 May 2006, orb 23). - Science case commissioning (16-27 May 2006, Orb 23-36). - Extended case commissioning (May 28-June 3, Orb 37-43). The ECC also occupied the first half of phase 1. The phase contained the first eclipse season that ends at orbit 40. VOI --- Dates : April 11 - May 13 2006 Orbits : 1 - 23 Phase 0 ------- Dates : May 14 - June 03, 2006 Orbits : 23 - 43 Phase duration : 20 days MTP : 1 Phase 1 ------- Phase 1 was favorable for observations of the evening terminator vicinity. In particular, the following observation were performed: - Cloud observations; - lightning on the night side; - stellar occultation on the dark limb (north/south asymmetry of the aerosol vertical structure); - Solar occultation (horizontal structure of hazes above the main cloud deck); - Thermal mapping of Ishtar Terra and Maxwell Montes; - Limb observations (vertical structure of haze layers); - Observations of nightglows (O2, NO ...), their latitude and vertical variability; - Bistatic sounding of the Maxwell Montes (BSR#1) - Comet Mrkos by SPICAV and VMC on June 5, 2006. SPICAV observed nadir and stellar occultations. VeRa performed bi-static sounding (BSR#1) of Maxwell Montes. VIRTIS observed the evening sector of the planet, night side mosaics, thermal mapping of Maxwell Montes and limbs. VMC observed the evening sector of Venus, limbs and perform thermal mapping of Maxwell Montes. Dates : June 4 - July 10, 2006 Orbits : 44-81 Phase duration : 37 days MTP : 2-3 Phase 2 ------- Phase 2 started at the beginning of the first Earth occultation season in orbit 81 and ended at the end of the 2nd eclipse season in orbit 145. It provided favorable conditions for nadir observations of the night side. The following observations had the priority: - Solar occultations; - Earth radio-occultations; - Night side dynamics with high spatial resolution - Twilight limb observations in forward scattering geometry - Nightglow observations - Thernal mapping of the surface The night side surface targets were Beta Regio, Theia Mons, Phoebe Regio, Ishtar Terra (Lakshmi Planum). ASPERA took measurement of the night side plasma. SPICAV observed in nadir mode and the solar occultations. VeRa observed during the Earth occultation season #1 and participate in the gravity campaign #1. VMC observed the night side: atmopsheric dynamic, night side surface mapping of the targets listed above. They observed also nightglow and they searched for lighting. Dates : July 11 - September 13 2006 Orbits : 81 - 145 Phase duration : 64 days MTP : 3-5 Phase 3 ------- The Venus dark side could be observed in the beginning of Phase 3. Phase 3 also had conditions for systematic observations of the morning/evening terminator and for solar corona studies. The phase contained the first superior solar conjunction (orbit 179-201). The following observations were performed: - Cloud at terminator (study of cloud and haze structure); - Coordinated campaign of atmospheric dynamics observations in Northern and Southern polar regions; - Search for lighting on the night side; - Double stellar occultation on the dark limb (north-south assymetry of aerosol vertical structure); Mapping of surface targets (Isthar Terra); - Limbs (vertical structure of haze layers); - Nightglows (O2, NO...): latitude and vertical variability; - Solar Corona studies; - Gravity anomaly #1 ASPERA observed the morning sector. SPICAV observed nadir and stellar occultations. VeRa observed the Solar Corona and do the 1st gravity anomaly campaign. VIRTIS observed the north/south polar dynamics, the Ishtar Terra night side target and the morning sector. VMC observed the north/south polar dynamics, the Ishtar Terra night side target, the high-resolution atmospheric dynamics and the nightglow and searched for lightning. Dates : September 14, 2006 - November 15, 2006 Orbits : 146 - 208 Phase duration : 62 days MTP : 5-7 Phase 4 ------- Phase 4 started at the beginning of the eclipse season in orbit 209 and ended at the end of the Earth occultation season in orbit 285. ASPERA observed in details the nightside plasma. SPICAV observed solar occultations and in nadir mode. VeRa observe during Earth occultation season and Solar Corona. VIRTIS and VMC observed on the dayside but also nightside of Theia Mons and Lakshmi Planum. Dates : November 16, 2006 - January 31, 2007. Orbits : 209 - 285 Phase duration : 76 days MTP : 7-10 Phase 5 ------- Phase 5 started at the end of the Earth occultation season #2 and ended at the beginning of the eclipse season #4. It had favorable conditions for observations of the evening terminator. Focus was also made on the night side. The following observations were performed: - Cloud observations at terminator (study of cloud and haze structure); - North-South atmospheric dynamics; - Search for lightning on the night side; - Double stellar occultation on the dark limb (north-south assymetry of aerosol vertical structure); - Mapping of surface targets: Atla Regio, Ozza Mons; - Limbs (vertical structure of haze layers); - Nightglows (O2, NO...): latitude and vertical variability; ASPERA observed in details the evening sector. SPICAV observed nadir and stellar occultation. VeRa did not observe anything. VIRTIS and VMC did mosaic and off pericentre observations. They participated in the North/South pole dynamics campaign. They also observed the night side. Dates : February 1 - March 15, 2007. Orbits : 286 - 329 Phase duration : 43 days MTP : 10-12 Phase 6 ------- Phase 6 started at the beginning of the eclipse season #4 in orbit 330. It ended with the same season in orbit 369. The phase provided good conditions for observations of the night side and atmospheric sounding in solar occultation geometry. Solar occultations were used to study composition and structure of the atmosphere above the cloud top. Campaigns of off-pericentre observations and apocentre VIRTIS mosaic were used to study composition and dynamics of deep atmosphere on the night side. Conditions was also favourable for observations of nightglows to study composition and dynamics of the thermosphere and search for lightning. Limb observations in forward scattering geometry (spacecraft in eclipse) provided good opportunity to study vertical structure of hazes above the main cloud. Thermal mapping of the surface and search for active volcanism was performed. One bi-static sounding experiment (BSR #4) was scheduled. The night side surface targets were Beta Regio, Theia Mons and Phoebe Regio. SPICAV observed nadir and Solar occultations. VeRa did the bi-static sounding experiment #4. VIRTIS and VMC observed off-pericentre and in mosaic mode. They observed Themis and Phoebe Regio on the night side. Dates : March 16 - April 24, 2007. Orbits : 330 - 369 Phase duration : 39 days MTP : 12-13 Phase 7 ------- Phase 7 started with the Earth occultation season #3 in orbit 370 and ended with it in orbit 435. Proximity to the Earth created excellent conditions for bi-static sounding and radio-occultation experiment that could reach maximum sounding depth. It was used to study the atmosphere with high spatial resolution. As earlier in phases 1, 3, 5 the terminator sector of the planet was available for observations in this phase. Cloud structure and atmospheric dynamics were important goals. The night side surface targets were Gula and Sif Mons, Guinevere Planitia, Ishtar Terra, Atalanta Planitia, Atla Regio and Ozza. SPICAV observed nadir and stellar occultations. VeRa was on during the radio occultation season 4 and performed the bi-static radar experiment #5 (Ozza Mons). VIRTIS and VMC did off-pericentre and mosaic observations. They observed Ishtar Terra and Maxwell Montes on the night side. Dates : April 25 - June 29, 2007. Orbits : 370 - 435 Phase duration : 65 days MTP :13-15 Phase 8 ------- Phase 8 started and ended with the eclipse season #5 (orbit 436-487). Thus significant portion of orbits was devoted to solar occultation observations. This phase was favourable for investigation of dayside dynamics. Proximity to the Earth provided good conditions for solar corona studies and bi-static sounding. Gravity #2 target was Atalanta Planitia, which was poorly covered by the Magellan observations. The thermal mapping covers Beta Regio, Phoebe Regio. SPICAV observed nadir and solar occultation. VeRa did the gravity #2 experiment and bi-static radar sounding #6 (Beta Regio and Theia Mons). VIRTIS and VMC did off-pericentre and mosaic observations of the dayside. Dates : June 30 - August 20, 2007. Orbits : 436 - 487 Phase duration : 51 days MTP : 16-17 Phase 9 ------- Phase 9 contained the Earth occultation season #4. It wass favourable for observations of the vicinity of evening terminator. By the end of this season conditions for the off-pericentre night side observations was fulfilled. Main scientific focus of this phase was to provide observations of the evening terminator. The following observations were carried out: - Cloud observations at terminator (study of cloud and haze structure); - Search for lightning on the night side; - Double stellar occultation on the dark limb (north/south asymmetry of the aerosol vertical structure); - Grazing solar occultation (horizontal structure of the hazes above the main cloud deck); - Mapping of the surface targets; - Limb (vertical structure of haze layers); - Nightglows (O2, NO) and their latitude and vertical variability. The night side surface targets are Atalanta Planitia, coronae, Guinevere Planitia and Ishtar Terra. SPICAV observed nadir and stellar occultation. VeRa did the bi-static radar sounding #6a. VIRTIS and VMC observed the morning and evening sectors. Dates : August 21 - October 3, 2007. Orbits : 488 - 530 Phase duration : 42 days MTP : 17-19 Phase 10 -------- Phase 10 had no eclipse or occultation seasons. A routine sequence of off-pericentre observations followed by Nadir, limb or stellar occultations were carried out. The night side surface targets were Atla Regio (Sapas, Maat, Ozza Mons), Zemina corona. SPICAV SOIR did not make any observation during this phase (no occultations). Dates : October 4 - October 26, 2007. Orbits : 531 - 553 Phase duration : 22 days MTP : 19-20 Phase 11 -------- Phase 11 started with the eclipse season #6 in orbit 554. However, solar occultations was only possible from orbit 576 to 596 because of the temperature conditions due to the sun position. VIRTIS performed some airglow campaign in nadir and limb geometry. VMC observed the surface on the night side. The observation targets were Asteria Regio, Hinemoa, Gunda and Kawelu Planitia, Beta Regio (Rheja and Theja Mons) and Phoebe Regio. SPICAV observed stars at large distance, later in the phase. Two spot pointings were performed in orbit 561 and 571 (study of cloud scattering phase function). Gravity measurements were performed over Atalanta Planita in orbits 615, 617, 619, 621. Meteors occurred in orbit 555. Despite the solar occultation that began 27th October 2007, SOIR did not make any observation neither calibration until 25th November 2007, due to thermal reasons in Quadrature period. Dates : October 27, 2007- January 3, 2008. Orbits : 554 - 622 Phase duration : 68 days MTP : 20-22 Phase 12 -------- Phase 12 started with Earth occultation season # 5 and ended with the eclipse season # 7. Earth occultation season began in orbit 623 and ended in orbit 692. Pendulum observations were performed during all this phase. From orbit 659 to orbit 680, three periods overlapped: Earth occultations, Eclipse season, solar opposition. The solar opposition was favorable for apocentre mosaics by VIRTIS. The surface targets for this phase were Atahensik and Zimina Coronae, Atla Regio (Ozza Mons) and East from it and Atalanta Planitia. VIRTIS near-IR did temperature sounding in the same region. Then cross-correlation on results were made possible. From orbit 612 to 631 there was the VIRTIS apocentre mosaic season. Solar occultations and pendulum observations were mainly performed at the end of the phase (from orbit 690). VeRa had the priority for pericentre observations of the Southern Hemisphere. However, VeRa measurements were not possible from orbit 645 to 658 for NNO maintenance. Dates : January 3 - March 31, 2008. Orbits : 623 - 710 Phase duration : 87 days MTP : 22-25 Phase 13 -------- There was no specific season during most of phase 13. During this phase, pericentre observations, stellar occultation observations, limb observations at pericentre were performed. At the end of the phase 13, in orbit 769, the mission entered superior conjunction phase and telecommunication outage period (orbit 769 to 790) during which all science operations were suspended. Dates : April 1 - June 4, 2008. Orbits : 711 - 775 Phase duration : 64 days MTP : 25-28 Phase 14 -------- Phase 14 started with the eclipse season #8 and Earth occultation season #6. At the beginning of the phase, the superior solar conjunction prevented any science observations. The eclipse and Earth occultation seasons overlapped (orbit 777-821). The Earth occultation period lasted longer up to orbit 832. The targets for the surface observations were East flank of Atla Regio, Ozza Mons, Zevana and Paga Chasma. During this phase, there was a pericentre lowering campaign in orbits 814, 815, 821, 822, 829 and 830. VMC performed surface imaging and wind tracking. SPICAV did solar occultations (ingress and egress solar occultations in orbits 811-819), night and plane limbs and UV observations of the exosphere on the day side. Stellar occultations may have been performed in coordination with VeRa. They observed dayglow when flying perpendicular to terminator. Possibly sub-solar point tracking may have been performed by SOIR. VIRTIS performed night limbs together with SPICAV and surface imaging. The VeRa Earth occultation experiments began in orbit 817. Dates : June 5 - July 31, 2008. Orbits : 776 - 832 Phase duration : 56 days MTP : 28-30 Phase 15 -------- There was no specific season during phase 15. The pericentre lowering campaign that began in the previous phase ends at orbit 836 and occurred in orbits 836 and 837. SPICAV performed night limbs, plane limbs and stellar occultations. Later in the phase, SPICAV performed day side limbs. VMC performed wind tracking on the day side. VIRTIS did night side and terminator monitoring and limb observations together with SPICAV at the beginning of the phase. Later in the phase, day side and terminator monitoring was performed. Dates : August 1 - September 22, 2008. Orbits : 833 - 885 Phase duration : 52 days MTP : 30-32 Phase 16 -------- This phase started with Eclipse season (orbit 866 - 934). During phase 16, there was also a Mosaic season (orbit 903 - 969) and the Earth occultation season #7 (orbit 921 - 985). Pendulum observations were frequently used. There was a joint VIRTIS-SPICAV campaign of night side nadir airglow observations in equatorial zone. There was good opportunity for SOIR nadir observations. SPICAV performed solar occultation and limb observations. VMC performed monitoring, wind tracking on the day side, surface imaging between solar occultations. Around orbit 967, they performed night side imaging of Aphrodite Terra. VIRTIS performed day side monitoring, limb observations together with SPICAV. Later in the phase, VIRTIS also performed Mosaic at apocentre. VeRa performed radio occultations. VIRTIS suffered a failure of the M cooler on 27th October 2008. As a consequence, from this date, there was no M-IR data. Dates : September 23 - December 31, 2008. Orbits : 886 - 985 Phase duration : 99 days MTP : 32-35 Phase 17 -------- This phase started with the end of the Earth occultation season. On orbit 1001 started a new eclipse season. The mission ended at the end of the Eclipse season, at orbit 1045. SPICAV observed day and night limbs and do Solar Occultations. VMC observed night side imaging of the Aphrodite Terra (Ovda Regio, Atla Regio, Sapas Mons, Ganis Chasma) and Rusalka Planitia. VeRa did radio observation. VIRTIS did observations every second orbit. Dates : January 1 - March 1, 2009. Orbits : 986 - 1045 Phase duration : days MTP : 35-37 Phase 18 -------- This phase included inferior conjunction. There was no specific season. It focuses on the Venus morning sector. Every second orbit coordinated campaign of ground based observations were organised. SPICAV observed stellar occultations and day side tangential limbs. VMC did wind tracking in the evening sector and night side imaging of the western part of Aphrodite Terra (Ovda Regio, Monatum and Tellus Tessera, Tahmina and Aino Planitia). VIRTIS did terminator studies, limb observations with SPICAV and night side surface observations with VMC. VeRa did gravity experiment. Dates : March 2 - May 4 , 2009. Orbits : 1046 - 1109 Phase duration : days MTP : 38-39 Phase 19 -------- This phase started with the Eclipse season (#11), at orbit 1110. It ended when the Eclipse season ended, at orbit 1159. The day side observations had good illumination conditions. The night side surface observations were in eclipse. SPICAV observed solar and stellar occultations as well as day side tangential limbs. VMC did day side observations and night side imaging of the Atlanta and Rusalka Planitia and of Atahensik corona. VIRTIS observed on the day side and limb observations with SPICAV. Dates : May 5 - June 23 , 2009. Orbits : 1110 - 1159 Phase duration : days MTP : 40-41 Phase 20 -------- This phase started at the end of the Eclipse season (#11), at orbit 1160. It ended after the end of the Earth occultation season (#7) and during the following Eclipse season (#12). VeRa observed during the Earth occultation season and was given the priority. Night side surface targets: Llorona Planitia and Aphrodite Terra. SPICAV did nadir observations around terminator (SO2), solar occultation before pericentre, exospheric limb observation after pericentre. VMC observed night limb (O2 emission and surface) before pericentre and day side nadir after pericentre. They observed in spot pointing mode (see VEX_POINTING_MODE_DESC.TXT) for phase function studies (study of the same place with different light conditions). They also did VMC mosaic (see INSTRUMENT_MODE_DESC.TXT). VIRTIS-H observed meridional cross-sections. Dates : June 24 - Septembre 19 , 2009. Orbits : 1160 - 1247 Phase duration : days MTP : 41-44 Phase 21 -------- This phase started during the Eclipse season #12, at orbit 1248. During the Eclipse season, the night side of the surface was observed. At the end of the phase (orbits 1271-1275) there was the Drag Campaign #2, meaning that the pericentre pass was devoted to the spacecraft tracking by NNO and no observations within +/- 2 hours from the pericentre were foreseen. SPICAV SOIR was given the priority in pericentre observations. SPICAV observed solar occultation. They did a campaign of nadir night side observations (NO emission). They also observed exospheric limbs. VMC observed day side nadirs. They did mosaic and spot pointing for phase function studies (see phase 20). VeRa did gravity measurements . VIRTIS observed meridional cross sections of the night side. Dates : September 20 - October 17 , 2009. Orbits : 1248 - 1275 Phase duration : days MTP : 45 Phase 22 -------- This phase did not contain any peculiar season. It ended just at the beginning of the Earth occultation season (orbit 1335). The observations focused on the morning sector of the planet. In orbit 1332, there was an OCM. SPICAV followed their previous nadir night side campaign of NO emission. They also did nadir observations of SO2 around terminator. VMC did day side observations with off-track (see explanation above). They also observed night limbs. VIRTIS observed meridional cross-sections. Dates : October 18 - December 16 , 2009. Orbits : 1276 - 1335 Phase duration : 99 days MTP : 46-47 Phase 23 -------- This phase started at the beginning of the Earth occultation season #13 (orbit 1336). It contained both Earth and solar occultations , but Earth could not be made due to conjunction. From orbit 1359 to 1378, no science was performed due to telecommunication outage. SPICAV did solar occultations and exospheric limbs. VMC observed in pendulum mode and day side with off-track. Pendulum: the observation points to Nadir, then out to space, then back to Nadir, then back to space, etc., mimicking a pendulum movement. VIRTIS observed meridional cross sections. VeRa did not observe due to proximity of the conjunction. Dates : December 17 2009 - February 1 , 2010. Orbits : 1336 - 1382 Phase duration : days MTP : 48-49 Phase 24 -------- This phase had neither Earth nor solar occultations. It started at the end of the eclipse season (orbit 1382) and ended with the start of the new eclipse season (orbit 1447). The evening sector of the planet was observed. Drag campaign #3 was scheduled for the orbits 1395-1457 and was mainly contained in this phase. A pericentre OCM was scheduled in the orbit 1402 and another one in the orbit 1430. SPICAV observed stellar occultations and limbs with short pendulum every 2 orbit. VMC did pendulum, day side with off track and night limb observations. VIRTIS observed meridional cross sections. Dates : February 2 - April 6 , 2010. Orbits : 1383 - 1446 Phase duration : days MTP : 49-52 Phase 25 -------- This phase started with the eclipse season #14 at orbit 1447 and ended with it at orbit 1499. During this phase started the Earth occultation season #9 at orbit 1470. The night side surface of Venus was observed in eclipse. Gravity campaign #11 was scheduled for orbits 1461, 1463 and 1465. An apocentre OCM was scheduled in the orbit 1458. SPICAV observed stellar occultations, solar occultations and exospheric limbs. VMC observed on the day side (latitude tracking, VMC mosaic, spot pointing for cloud phase function). VIRTIS did meridional cross-sections. VeRa performed radio occultations. Dates : April 7 - May 29 , 2010. Orbits : 1447 - 1499 Phase duration : days MTP : 52-53 Phase 26 -------- This phase started at the end of the eclipse season #14 and ended at the end of the Earth occultation season #9. A pericentre OCM was scheduled in orbit 1500. SPICAV observed stellar occultation, limbs, nadir around terminator (SO2) and Earth. VMC observed on the day side (latitude tracking, VMC mosaic, spot pointing for cloud phase function). VeRa did radio occultations. VIRTIS-H observed meridional cross-sections. Dates : May 30 - July 11 , 2010. Orbits : 1500 - 1542 Phase duration : days MTP : 53-55 Phase 27 -------- This phase focused on the morning sector of the planet. It started at the end of the Earth occultation season #9 at orbit 1543 and ended at orbit 1560. The gravity campaign#12 initially scheduled was cancelled. SPICAV observed stellar occultations and limbs. They also observed nadir around terminator (SO2). VMC observed the day side with off track to the day side (latitude tracking, VMC mosaic, spot pointing for cloud phase function). VeRa did radio occultations and the gravity campaign #12, during the Earth occultation season. VIRTIS-H observed meridional cross-sections. Dates : July 12 - July 29 , 2010 Orbits : 1543 - 1560 Phase duration : 36 days MTP : 55-56 Phase 28 -------- This phase included the eclipse season #15. Solar occultation occurred after pericentre. Night surface observations in eclipse covered Thetis Regio of Aphrodite Terra and Llorona and Niobe Planitia. At egress, from eclispes the Artemis corona could be imaged. Surface targets: Thetis Regio, Llorona and Niobe Planitia, Artemis corona. Instrument specific observations: SPICAV did solar occultation observations after orbit 1571. There was some joint SPICAM-SPICAV observations of hydrogen distribution in solar corona. VIRTIS did day latitude track (off pericentre), day side spectroscopy (H) and night limb tracking surface (H) (pericentre). VMC did day side monitoring (off pericentre), latitude tracking, day limb tracking and night limb tracking (pericentre). Dates : July 30 - September 13, 2010. Orbits : 1561 - 1606 Phase duration : 45 days MTP : 56-57 Phase 29 -------- This phase focused on the evening sector of the planet. Drag Campaing #4 (1648-1654) occurred during this phase. After the Drag campaign, the pericenre was raised to 340km. During this phase Venus approached inferior conjunction. Surface imaging was possible either from apocentre by VIRTIS or at close approach by VMC. Intrument specific observations: SPICAV did solar occultation (pericentre) and stellar occultations (off pericentre). SPICAV SOIR did calibrations and observed aeronomic emissions at pericentre. SOIR calibrations consisted in 2 miniscans, 1 alignement and 1 thermal performed in any part of the orbit outside the eclipse. VIRTIS did day latitude track full mosaic (off pericentre) and, at pericentre, day spectroscopy (H) and night limb tracking (H). VMC did day side monitoring and observe terminator (off pericentre) and, at pericentre, latitude day tracking, day limb tracking, and surface out of eclipse. Dates : September 14 - November 18 , 2010. Orbits : 1607 - 1671 Phase duration : 64 days MTP : 57-59 Phase 30 -------- This phase included Eclipse season #16. It also coincided with Akatsuki's arrival. Akatsuki is a Japanese spacecraft (JAXA) sent on May 20, 2010 to study Venus Atmosphere dynamics. Unfortunately, the Akatsuki experienced some problems during the orbit insertion manoeuvre and failed to get captured in Venus orbit. During this phase, solar occultation occurred before pericentre. Surface Targets: Thesis, Ovda Regio of Aphrodite Terra, Tellus Tessera, Niobe and Llorona Planitia, Artemis corona. Instrument specific observations: SPICAV SOIR did calibrations and was given priority in pericentre observations. SPICAV did stellar occultations (off peri) and observed exosperic limb (peri). VIRTIS did day latitude track (off peri) and, at pericentre, spectra and night limb (M). VMC did day side monitoring (off peri) and observed surface and limb in eclipse at pericentre. Dates : November 19, 2010 - January 16, 2011. Orbits : 1672 -1731 Phase duration : 59 days MTP : 60-61 Phase 31 -------- This phase included Earth occultation #10 and the beginning of eclipse season #17. No solar occultation was possible during this phase. Instrument specific observations: SOIR did calibrations (off peri). SPICAV observed stellar occultations (off peri) and at pericentre, NO emission mapping in nadir, SO2 at terminator. There was also joint SPICAV SPICAM observations. VeRa did radio occultations. VIRTIS did day latitude track off pericentre and at pericentre, limb scans and day spectra. VMC did day side monitoring off pericentre and observed morning sector and evening sector at pericentre. Dates : January 17 - March 22, 2011. Orbits : 1732 - 1796 Phase duration : 64 days MTP : 62-63 Phase 32 -------- This phase included Eclipse season #17. Surface targets: Ovda and Thesis Regio, Manatum and Tellus Tessera, Niobe and Tahmina Planitia. Instrument specific observations: SPICAV SOIR did calibrations (off peri) and solar occultations (peri). SPICAV did joint observation with SPICAM and stellar occultations (peri). VeRa did radio occultations. VIRTIS did day latitude track off pericentre and spectra and limb scan at pericentre. VMC did day side monitoring off pericentre and, at pericentre, day latitude tracking and surface observations. Dates : March 23 - April 25 , 2011. Orbits : 1797 - 1830 Phase duration : 33 days MTP : 64-65 Phase 33 -------- This phase included Drag campaign #5. The pericentre was as low as 165 km and was raised to 290 km after the campaign. Instrument specific observations: SPICAV did joint observations with SPICAM off pericentre. At pericentre SPICAV observed nadir for SO2 measurements, did limb observations and stellar occultations. VIRTIS did a full mosaic off pericentre and at pericentre observed day spectroscopy and night limb. VMC observed the terminator off pericentre and, at pericentre, the surface and the limb. Dates : April 26 - June 13 , 2011. Orbits : 1831 - 1879 Phase duration : 48 days MTP : 66-67 Phase 34 -------- This phase included both Earth occultation season #11 and eclipse season #18. From orbit 1895 to 1907, Venus, Earth and Sun were on one line. Radio and solar occultations sounded approximately the same regions on Venus. This created a rare opportunity for co-located soundings by VeRa and SOIR. Surface targets: Ovda Region, Manatum and Tellus tessera. Instrument specific observations: SOIR performed calibrations off pericentre and solar occultations (peri). SPICAV did joint observations with SPICAM and stellar occultations off pericentre and, at pericentre, observed zodacial light and exospheric limb. VIRTIS did off pericentre day latitude tracking. They observed limb and did M spectral measurement at pericentre. They suffered a failure in the H cooler on June, 13th 2011. From this date, there was no H data. VMC did day side monitoring off pericentre and, at pericentre, they observed the limb and the surface. Dates : June 14 - August 26 , 2011. Orbits : 1880 - 1953 Phase duration : 73 days MTP : 67-69 Phase 35 -------- This phase included Drag campaign #6. Instrument specific observations: SOIR performed off pericentre calibrations. SPICAV did off pericentre joint observation with SPICAM. They also did stellar occultations off pericentre. At pericentre they did SO2 measurements in nadir modes and at terminator. VIRTIS did day latitude track (off peri). At pericentre they did limb scans and spectral measurements. VMC did day side monitoring at terminator (off peri) and day latitude tracking at pericentre. Dates : August 27 - October 24 , 2011. Orbits : 1954 - 2012 Phase duration : 58 days MTP : 70-71 Phase 36 -------- This phase included Eclipse season #19 and the first half of Earth occultation #12. Surface targets: Manatum Tessera, Tahmina Platinia, Tellus Tessera, Niobe Planitia and Ovda regio. Instrument specific observations: SOIR performed off pericentre calibrations and solar occultations at pericentre. SPICAV did joint observations with SPICAM and stellar occultations off pericentre. At pericentre, they observed zodacial light. VIRTIS did off pericentre day latitude track. At pericentre, they did limb scans, measure day spectra. VMC did off pericentre day side monitoring. At pericentre, they did day latitude tracking and observed the surface. Dates : October 25 - December 04 , 2011. Orbits : 2013 - 2053 Phase duration : 40 days MTP : 72- 73 Phase 37 -------- This phase included the second half of Earth occultation season #12. Instrument specific observations: SPICAV did tangential limb and stellar occultations at pericentre. VeRa did radio occultations. VIRTIS did off pericentre day latitude track and full mosaic. At pericentre, they did day spectroscopy and night limb tracking. VMC did day side monitoring off pericentre. At pericentre they did day latitude tracking and observed the surface. Dates : December 5, 2011 - January 07 , 2012. Orbits : 2054 - 2087 Phase duration : 33 days MTP : 74 Phase 38 -------- This phase included Drag campaign #7. The pericentre was as low as 165km. Instrument specific observations: SOIR performed calibration off pericentre. SPICAV did off pericentre stellar occultations. At pericentre, they observed nadir mode at terminator and measured aeronomic emissions. VIRTIS did day side tracking off pericentre, 2 full mosaics. At pericentre, they did limb tracking. VMC observed the surface, the limb and did day latitude tracking at pericentre. Dates : January 8, 2012 - February 4, 2012 Orbits : 2088 - 2115 Phase duration : 27 days MTP : 75 From this phase, there were two new observation types defined for SPICAV and SPICAV SOIR . The first one were observations in eclipse of the NO airglow using inertial mode. The spacecraft is held in inertial mode such that the observed point sweeps a wide range of latitudes while the spacecraft is in eclipse. The second one done by SOIR intended to observe light reflected from the dayside cloud top. MTP 76 -------- This phase included the start of an eclipse season in orbit 2119. The solar occultation occured before pericentre. Phase 39 and 40 were an opportune time for two campaigns. Before pericentre (nightside), every other orbit was allocated to VIRTIS-MVIS night limb search for airglow. After pericentre (dayside), this MTP could be used for SPICAV dayside limb observations of airglow. Surface targets: Ishtar Terra in the Northern Hemisphere; Central Eistla Regio, Lada Terra (Southern hemisphere), Bereghinia Planitia (28°E, 39°N). VIRTIS: Mosaic from apocentre, limb track airglow observations SPICAV: Sub-solar point observation, for Cross Polarization calibration, Zodiacal Light Observation during eclipse. SOIR: nadir observation. SPICAV and VIRTIS: nadir observations at pericentre (optimised for nadir absorption spectroscopy. VMC: phase function observations, mosaics of dayside at pericentre. Dates : February 5, 2012 -March 3, 2012 Orbits : 2116 - 2143 Phase duration : 27 days MTP : 76 MTP 77 -------- The entire phase was in eclipse season. The long Earth occultation season started at the end of this phase (in orbit 2167). Surface targets: Ishtar Terra, Bell Regio (e.g. Tepev Mons), E. Eistla Regio. VIRTIS: M-VIS limb-track observations (night side in eclipse). SPICAV: Stellar occultation, VEX-SOHO joint observations. SOIR: Solar occultations. VeRa: Radio occultations. Dates : March 4, 2012 - March 31, 2012 Orbits : 2144 - 2171 Phase duration : 27 days MTP : 77 MTP 78 -------- The eclipse season ended in orbit 2178. The long Earth occultation season continued throughout the phase. Atmospheric Drag Campaign #8 occurred during this phase. Surface targets: Ovda Regio, Tellus Tessera. VeRa: Ingress passes probing low latitudes, radio occultation passes in pure Earth-pointing combined with the drag passes (TRQ only). VIRTIS-M-VIS: search for airglow, global spectro-imaging from apocentre. SPICAV: Stellar occultation. No SOIR observation. Dates : April 1, 2012 - April 28, 2012 Orbits : 2172 - 2199 Phase duration : 27 days MTP : 78 MTP 79 -------- The long Earth occultation season continued throughout the phase. The beginning of the phase (orbits 2196-2207) saw continuation of Atmospheric Drag experiment #8. Almost every pericentre pass was reserved for radio science. Surface targets: Lada Terra. VeRa: occultations during drag passes in pure Earth-pointing mode, from orbits 2204-2224 a campaign of consecutive VeRa ingress occultations on every orbit probed repeatedly the same latitude (~30-35°S). VMC: meteor showers (TBC) VIRTIS-M-VIS: cloud morphology imaging in spot-tracking mode Dates : April 29, 2012 - May 26, 2012 Orbits : 2200 - 2227 Phase duration : 27 days MTP : 79 MTP 80 -------- This MTP included the inferior conjunction, at which a transit of Venus occurred (6 June 2012, 01:29:35 UT, Orbit 2238). The long Earth occultation season continued throughout the whole of this phase. Eclipse season started on June, 6th, orbit 2238. This TMP contained the Venus Transit (June 6th 2012). Special observations due to Venus Transit: - VIRTIS off pericentre observations. - SOIR grazing occultation - Limb imaging from SPICAV - VMC sufferred an anomaly that shut down the instrument on 4 June 2012, Orbit 2236 at 01:42Z. - SPICAV UV imaging of the Sun immediately prior to the transit day, in Orbit 2237 (05-Jun-2012, DOY157), for cross calibration with ISS/SOLSPEC Surface targets: Ishtar Terra, C. Eistla Regio, Bereghinia Planitia, Lada Terra in the S hemisphere. VIRTIS: high resolution morphology observation close to pericentre, atomic oxygen airglow monitoring before and after each eclipse season. VeRa: activity after orbit 2238, start of eclipse season. SPICAV: SPICAM/SPICAV observations near apocentre at orbits 2248-2250 Dates : May 27, 2012 - June 23, 2012 Orbits : 2228 - 2255 Phase duration : 27 days MTP : 80 MTP 81 -------- The long Earth occultation season continued throughout this phase. Eclipse season ended on July 15th (orbit 2077). Surface targets: Ishtar Terra, Bell Regio (e.g. Tepev Mons), E. Eistla Regio. Instrument specific observations: - SOIR: consecutive observations in orbits 2256-2261 to search for day-to-day variability at high latitudes and to probe latitudes > 70°S. - VeRa: from orbits 2254-2266 a campaign of consecutive VeRa ingress occultations on every orbit probed repeatedly the same latitude (~20°N). - VIRTIS: hi-resolution cloud morphology imaging by VIRTIS-M-VIS, atomic oxygen airglow monitoring before and after each eclipse season, two apocentre mosaic campaigns. Dates : June 24, 2012 - July 21, 2012 Orbits : 2256 - 2283 Phase duration : 27 days MTP : 81 MTP 82 -------- The long Earth occultation season continued throughout this phase. Atmospheric Drag Experiment campaign #9 starts on 14 August 2012 (orbits 2307-2325). Surface targets: No particular targets. Instrument specific observations: - VEX-SOHO observation carried out in orbits 2308-2310. Dates : July 22, 2012 - August 18, 2012 Orbits : 2284 - 2311 Phase duration : 27 days MTP : 82 MTP 83 -------- The long Earth occultation season continued throughout this phase. Atmospheric Drag Experiment campaign #9 continued in this MTP, until 1 September (orbits 2307-2325). Surface targets: No particular targets. Instrument specific observations: - VIRTIS: atomic oxygen airglow monitoring before and after each eclipse season. Dates : August 19, 2012 - September 15, 2012 Orbits : 2312 - 2339 Phase duration : 27 days MTP : 83 MTP 84 -------- The long Earth occultation season #3 finished at the end of this MTP (orbit 2360, 06 Oct 2012). Eclipse season #22 starts in orbit 2343. Surface targets: Surface targets: Maxwell Montes, W. Eistla Regio (Sif Mons, Gula Mons), Dione Regio (Innini Mons). Instrument specific observations: - VMC: Near-zero phase angle campaign (after pericentre). - SPICAV: NO observation campaign. Dates : September 16, 2012 - October 13, 2012 Orbits : 2340 - 2367 Phase duration : 27 days MTP : 84 MTP 85 -------- Eclipse season continued throughout this MTP. Surface targets: Bell Regio, C. Eistla. Instrument specific observations: - VMC: Near-zero phase angle campaign (after pericentre). - SPICAV: NO observation campaign to map NO airglow across nightside, using an inertial pointing. Dates : October 14, 2012 - November 10, 2012 Orbits : 2368 - 2395 Phase duration : 27 days MTP : 85 MTP 86 -------- Eclipse season finished in orbit 2404 (19 Nov 2012). Pre-drag campaign passes, followed by the beginning of drag campaign #10 on the 4 December 2012 (orbit 2419). Surface targets: No particular targets. Instrument specific observations: - VIRTIS: Atomic oxygen airglow monitoring before and after each eclipse season in orbits2419-2430. Dates : November 11, 2012 - December 08, 2012 Orbits : 2396 - 2423 Phase duration : 27 days MTP : 86 MTP 87 -------- Earth occultation season #14 started in orbit 2445 (30 December 2012). Drag campaign #10 continues until the 15 December 2012 (orbit 2430). Surface targets: Mielikki Mons, Inninni Mons. Special observations: - Dayside limb imaging campaign to study vertical profiles of clouds & hazes. Dates : December 09, 2012 - January 05, 2013 Orbits : 2424 - 2451 Phase duration : 27 days MTP : 87 MTP 88 -------- Surface targets: Instrument specific observations: Dates : January 06, 2013 - February 02, 2013 Orbits : 2452 - 2479 Phase duration : 27 days MTP : 88 MTP 89 -------- Surface targets: Instrument specific observations: Dates : February 03, 2013 - March 02, 2013 Orbits : 2480 - 2507 Phase duration : 27 days MTP : 89 MTP 90 -------- Surface targets: Instrument specific observations: Dates : March 03, 2013 - March 30, 2013 Orbits : 2508 - 2535 Phase duration : 27 days MTP : 90 MTP 91 -------- Surface targets: Instrument specific observations: Dates : March 31, 2013 - April 27, 2013 Orbits : 2536 - 2563 Phase duration : 27 days MTP : 91 MTP 92 -------- Surface targets: Instrument specific observations: Dates : April 28, 2013 - May 25, 2013 Orbits : 2564 - 2591 Phase duration : 27 days MTP : 92 MTP 93 -------- Surface targets: Instrument specific observations: Dates : May 26, 2013 - June 22, 2013 Orbits : 2592 - 2619 Phase duration : 27 days MTP : 93 MTP 94 -------- Surface targets: Instrument specific observations: Dates : June 23, 2013 - July 20, 2013 Orbits : 2620 - 2647 Phase duration : 27 days MTP : 94 MTP 95 -------- Surface targets: Instrument specific observations: Dates : July 21, 2013 - August 17, 2013 Orbits : 2648 - 2675 Phase duration : 27 days MTP : 95 MTP 96 -------- Surface targets: Instrument specific observations: Dates : August 18, 2013 - September 14, 2013 Orbits : 2676 - 2703 Phase duration : 27 days MTP : 96 MTP 97 -------- Surface targets: Instrument specific observations: Dates : September 15, 2015 - October 12, 2013 Orbits : 2704 - 2731 Phase duration : 27 days MTP : 97 MTP 98 -------- Surface targets: Instrument specific observations: Dates : October 13, 2013 - November 09, 2013 Orbits : 2732 - 2759 Phase duration : 27 days MTP : 98 MTP 99 -------- Surface targets: Instrument specific observations: Dates : November 10, 2013 - December 07, 2013 Orbits : 2760 - 2787 Phase duration : 27 days MTP : 99 MTP 100 -------- Surface targets: Instrument specific observations: Dates : December 08, 2013 - January 04, 2014 Orbits : 2788 - 2815 Phase duration : 27 days MTP : 100 MTP 101 -------- Surface targets: Instrument specific observations: Dates : January 05, 2014 - February 11, 2014 Orbits : 2816 - 2843 Phase duration : 27 days MTP : 101 MTP 102 -------- Surface targets: Instrument specific observations: Dates :February 12, 2014 - March 01, 2014 Orbits : 2844 -2871 Phase duration : 27 days MTP : 102 Eclipse season Eclipse Dates Season # ------------------------------------- 1 | 16 Apr 2006 - 31 May 2006 2 | 6 Aug 2006 - 13 Sep 2006 3 | 16 Nov 2006 - 10 Jan 2006 4 | 17 Mar 2007 - 26 Apr 2007 5 | 29 Jun 2007 - 21 Aug 2007 6 | 27 Oct 2007 - 9 Dec 2007 7 | 9 Feb 2008 - 1 Apr 2008 8 | 6 Jun 2008 - 20 Jul 2008 9 | 23 Sep 2008 - 10 Nov 2008 10 | 16 Jan 2009 - 28 Feb 2009 11 | 5 May 2009 - 23 Jun 2009 12 | 27 Aug 2009 - 17 Oct 2009 13 | 17 Dec 2009 - 1 Feb 2010 14 | 7 Apr 2010 - 29 May 2010 15 | 30 Jul 2010 - 13 Sep 2010 16 | 18 Nov 2010 - 10 Jan 2011 17 | 13 Mar 2011 - 25 Apr 2011 18 | 29 Jun 2011 - 25 Aug 2011 19 | 25 Oct 2011 - 04 Dec 2011 20 | 08 Feb 2012 - 07 Apr 2012 21 | 06 Jun 2012 - 15 Jul 2012 22 | 19 Sep 2012 - 19 Nov 2012 23 | 18 Jan 2013 - 23 Feb 2013 24 | 1 May 2013 - 2 Jul 2013 25 | 31 Aug 2013 - 5 Oct 2013 26 | 11 Dec 2013 - 12 Feb 2014 ------------------------------------- Earth occultation Season Occultation Dates Season # ------------------------------------- 1 | 11 Jul 2006 - 30 Aug 2006 2 | 22 Nov 2006 - 31 Jan 2007 3 | 26 Apr 2007 - 1 Jul 2007 3a | 4 Sep 2007 - 18 Sep 2007 4 | 4 Jan 2008 - 13 Mar 2008 5 | 5 Jun 2008 - 1 Aug 2008 6 | 28 Oct 2008 - 31 Dec 2008 7 | 16 Jul 2009 - 19 Sep 2009 8 | 10 Dec 2009 - 8 Feb 2010 9 | 30 Apr 2010 - 11 Jul 2010 10 | 17 Jan 2011 - 22 Mar 2011 11 | 14 Jun 2011 - 25 Aug 2011 12 | 15 Nov 2011 - 06 Jan 2012 13 | 27 Mar 2012 - 06 Oct 2012 14 | 30 Dec 2012 - 16 Feb 2013 15 | 9 May 2013 - 29 Jul 2013 16 | 26 Oct 2013 - 23 Mar 2014 ------------------------------------ Solar conjunction (superior) Solar Dates Conjunction # ------------------------------------- 1 | 17 Oct 2006 - 8 Nov 2006 2 | 29 May 2008 - 19 Jun 2008 3 | 26 Dec 2009 - 28 Jan 2010 4 | 06 Aug 2011 - 26 Aug 2011 5 | 18 Mar 2013 - 8 Apr 2013 ------------------------------------- Drag Campaign = DC# | Dates | --------------------------------------- 1 | 01 Aug 2008 - 22 Aug 2008 | 2 | 12 Oct 2009 - 18 Oct 2009 | 3-1 | 22 Feb 2010 - 28 Feb 2010 | 3-2 | 11 Apr 2010 - 16 Apr 2010 | 4(TBC)| 13 Oct 2010 - 25 Oct 2010 | 5(TBC)| 23 May 2011 - 03 Jun 2011 | 6(TBC)| 13 Sep 2011 - 24 Sep 2011 | 7 | 08 Jan 2012 - 19 Jan 2012 | 8 | 25 Apr 2012 - 06 May 2012 | 9 | 14 Aug 2012 - 01 Sep 2012 | 10 | 06 Nov 2012 - 15 Dec 2012 | 11 | not possible | 12 | 15 Jul 2013 - 27 Jul 2013 | 13 | 29 Oct 2013 - 09 Nov 2013 | --------------------------------------- Gravity = Grav# | Dates | --------------------------------------- 1 | 01 Sep 2006 - 10 Sep 2006 | 2 | Cancelled | 3 | 27 Dec 2007 - 02 Jan 2008 | 4 | 09 Mar 2009 - 15 Mar 2009 | 5 | 21 Mar 2009 - 27 Mar 2009 | 6 | 15 Apr 2009 - 19 Apr 2009 | 7 | 27 Apr 2009 - 01 May 2009 | 8 | 25 May 2009 - 31 May 2009 | 9 | 25 Jun 2009 - 01 Jul 2009 | 10 | 01 Oct 2009 - 07 Jul 2009 | 11 | 21 Apr 2010 - 25 Apr 2010 | 12 | 14 Jul 2010 - 20 Jul 2010 | --------------------------------------- Spacecraft events = Event | Dates | ---------------------------------------------------------------| Launch | 09 Nov 2005 | Earth Moon observations | 22/23 Nov 2005 | Pointing Test 1 | 27 Nov 2005 - 04 Dec 2005 | Interference Test | 14 Dec 2005 - 15 Dec 2005 | Pointing Test 2 | 16 Jan 2006 - 21 Jan 2006 | VOI | 11 Apr 2006 | Capture Orbit Observation 0 | 12 Apr 2006 | Capture Orbit Observation 1 | 13 Apr 2006 | Capture Orbit Observation 2 | 14 Apr 2006 | Capture Orbit Observation 3 | 16 Apr 2006 | Capture Orbit Observation 4 | 17 Apr 2006 | Capture Orbit Observation 5 | 19 Apr 2006 | First Operational orbit | 07 May 2006 | (17th Apocentre) | | Case Commissioning Start | 14 May 2006 | Extended Case Commissioning Start | 24 May 2006 | Nominal Science Start MTP002 | 04 Jun 2006 | Safe Mode 01 | 13 Jun 2006 | Mission Commissioning Results | 04 Jul 2006 | Review | | Safe Mode 02 | 25 Aug 2006 18:15 UTC | Safe Mode 03 | 22 Sep 2006 19:24 UTC | Safe Mode 04 | 27 Sep 2006 04:37 UTC | Safe Mode 05 | 09 Oct 2006 04:20 UTC | VIRTIS-H and VIRTIS-M shutdown | 13 Aug 2007 | due to cooling Motors | | VIRTIS-M restarted | 31 Aug 2007 | Payload Off due to SADE-A | 25-27 Aug 2007 | misalignment | | VIRTIS-H restarted | 04 Nov 2007 | Safe Mode 06 | 27/28 Jan 2008 | VIRTIS-M cooler failure | 27 Oct 2008 23:58 | VIRTIS-M unit resumed non cooler | 28 Jan 2009 | operations in only the | | visible channel | | VMC SSMM overflow | 11 March 2009 | Safe Mode 07 | 30 Jul 2010 02:54 UTC - | | 31 Jul 2010 16:03 UTC | VIRTIS-H cooler failure | 13 Jun 2011 22:33 UTC - ? | Operations Shutdown due to Star | 7 Mar 2012 12:00 UTC - | Tracker blindness (Solar Flare) | 12 Mar 2012 13:26 UTC | ---------------------------------------------------------------- Moreover, about every 6 months a SSMM problem (named SCET problem) occurs for about 15 minutes. During this time, the spacecraft cannot record data and the data is lost. This problem does not really affect archive but it is put in the mission catalog as a general information.
Creator Contact Martin Paetzold
Date Published 2015-12-01T00:00:00Z
Publisher And Registrant European Space Agency
Credit Guidelines European Space Agency, Martin Paetzold, 2015, VEX-V-VRA-1-2-3-EXT2-0646, V1.0, European Space Agency, https://doi.org/10.5270/esa-phewhup