DATA_SET_DESCRIPTION |
Data set Overview : The CODMAC level 5 science data consist in time series (local density) covering the Extension phase 2 for the major species H2O, CO, O2, and CO2. Rosetta was at distances between 6.7 and 200 km from the comet during this time. ROSINA was permanently analysing the coma of the comet with DFMS and COPS sensors and the RTOF sensor part of the time (instrument performance permitting), except during wheel offloadings, when the mass spectrometers DFMS and RTOF were in standby, and during orbit control manoeuvres, when all sensors were off. Explanations on the data generation of the ROSINA sensors can be found in the OPERATION_LOGBOOK.ASC. 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 : The level 5 data products are based on the COPS L2 PDS, DFMS L3 PDS, and RTOF L3 PDS calibrated products. Processing : The processing of the RTOF and DFMS CODMAC L3 to L5 PDS derived data is detailed in the ROSINA_PDS_L3_TO_L5.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.
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