NSSDCA ID: PSSB-02314
Availability: Archived at NSSDC, accessible from elsewhere
This description was generated automatically using input from the Planetary Data System.
Data set Version 2.0 ==================== The Science RIDs from the October 2018 review have been applied to this ROSINA dataset. Major species (H2O, CO, O2, and CO2) were used producing the V1.0 of the L4 datasets, minor species (CH4, NH3, HCN, H2CO, C2H6, CH3OH, H2S, C2H5OH, OCS, CS2) detected by DFMS were added for the V2.0 of the L4 datasets. As a result, V2.0 of this CODMAC L4 dataset has been created, using the COPS and DFMS science data from the CODMAC L2 V2.0 (COPS) and CODMAC L3 V2.0 (DFMS) datasets. These changes also affect the structure of the PDS files: columns with references to the files used to extract the minor species densities have been added, and therefore the local density and the statistical uncertainty values have been changed. Data set Overview ================= Rosetta was at distances between 26.89 and 0 km from the comet during this time. The COPS HK packet was generated every 4s during the last hour of the mission. ROSINA was permanently analysing the coma of the comet with all three sensors, except during wheel offloadings, when the mass spectrometers DFMS and RTOF were in standby and during orbit control manoeuvers, when all sensors were off. Explanation on the data generation of the ROSINA sensors can be found in the OPERATION_LOGBOOK.ASC This volume contains a dataset of ROSINA pressure records of the combined comet and Rosetta spacecraft outgassing during Extension phase 3. The calibration data can be found in the level 3 volume. The volume also contains documentation and index files to support access and use of the data. Parameters ========== DFMS and RTOF data contain neutral gas data as well as ion data. The data are raw, uncalibrated data. COPS data contains nude gauge pressure values of the combined spacecraft and cometary signal. For calibrated data we refer the user to the level 3 data. Calibration =========== COPS data are calibrated. However, the calibration factor has been determined for nitrogen gas, and may not be appropriate for the coma composition. To properly calibrate the COPS densities and process the L4 PDS data, the molecular ratios from the DFMS CODMAC L3 PDS have to be taken into account to correct the COPS L2 PDS. Processing ========== The processing of the COPS CODMAC L2 to L4 PDS derived data is detailed in the COPS_PDS_L2_TO_L4.PDF document. Software ======== No software will be provided. Media/Format ============ The standard distribution format for the data is an electronic volume. 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 product are relative to the Earth Mean Equator and Equinox reference frame of J2000. SUB_SPACECRAFT_LATITUDE, SUB_SPACECRAFT_LONGITUDE are given in the Cheops reference frame. The SPACECRAFT_ALTITUDE gives the distance to the spacecraft from the target center of mass. These parameters are computed at time t=START_TIME. Distances are given in km, angles in degrees. Cheops Reference Frame ====================== Scholten, F., Preusker, F., Jorda, L, and Hviid, S., Reference Frames and Mapping Schemes of Comet 67P/C-G, RO-C-MULTI-5-67P-SHAPE-V1.0:CHEOPS_REF_FRAME_V1, NASA Planetary Data System and ESA Planetary Science Archive, 2015.
These data are available on-line from the Planetary Data System (PDS) at:
https://pdssbn.astro.umd.edu/holdings/ro-c-rosina-4-ext3-v2.0/
Questions and comments about this data collection can be directed to: Dr. David R. Williams
Name | Role | Original Affiliation | |
---|---|---|---|
Prof. Kathrin Altwegg | General Contact | Universitat Bern | altwegg@phim.unibe.ch |