Data set Overview : Rosetta was at distances between 80 and 220 km from the comet during this time, except during a close flyby on March 28, 2015. ROSINA was permanently analyzing 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 manoeuvers, when all sensors were off. The explanation of the generated data 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 contain pressure data of the background pressure and of some thruster firings from the nude gauge. 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 the coma composition. For this the data from RTOF or DFMS have to be taken into account.   Note on the DFMS and RTOF data: The user of our level 2 data has to make the conversion from pixel to mass and from ADC counts to ion current himself. In this way he will be aware that the precision is limited and depends on many parameters and he will use the data accordingly. The procedure required to calibrate the DFMS is described in our User manual, Annex D1 (DOCUMENT directory). ROSINA team are currently developing the necessary algorithms, putting emphasis on the quality control for the algorithm. They are defining quality flags for the data which will then tell the user how well the mass scale and the intensity scale have been defined. They are also working to produce level 3 data with calibrated mass scale and intensity. Once this SW is in place they will produce calibrated data for the mission at the comet.   Processing : No processing was applied to the data.   Software : No software is 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.

Confidence Level Overview : All data have been validated by the ROSINA team and found as expected. Any exceptions are noted by the DATA_QUALITY field in the label files.