NSSDCA ID: PSSB-01216
Availability: Archived at NSSDC, accessible from elsewhere
This description was generated automatically using input from the Planetary Data System.
Data Set Overview ================= The data from the ROSETTA PLASMA CONSORTIUM (RPC) Fluxgate Magnetometer(MAG)was submitted by Ingo Richter (TM) for the RPCMAG team. The PI of the team is Karl-Heinz Glassmeier. The data have been measured during the EXTENDED MISSION PHASE 1 (EXT1) of ROSETTA. Included are the following sub-phases: MTP0025 - STP0091 from 2016-01-12T23:25 to 2016-01-19T23:25 MTP0025 - STP0092 from 2016-01-19T23:25 to 2016-01-26T23:25 MTP0025 - STP0093 from 2016-01-26T23:25 to 2016-02-02T23:25 MTP0025 - STP0094 from 2016-02-02T23:25 to 2016-02-09T23:25 MTP0026 - STP0095 from 2016-02-09T23:25 to 2016-02-16T23:25 MTP0026 - STP0096 from 2016-02-16T23:25 to 2016-02-23T23:25 MTP0026 - STP0097 from 2016-02-23T23:25 to 2016-03-01T23:25 MTP0026 - STP0098 from 2016-03-01T23:25 to 2016-03-08T23:25 MTP0027 - STP0099 from 2016-03-08T23:25 to 2016-03-15T23:25 MTP0027 - STP0100 from 2016-03-15T23:25 to 2016-03-22T23:25 MTP0027 - STP0101 from 2016-03-22T23:25 to 2016-03-30T11:25 MTP0027 - STP0102 from 2016-03-30T11:25 to 2016-04-05T23:25 All magnetic field data are calibrated, resampled data. That means the data represent the 3 components of the magnetic field measured in physical units (nT). Calibration has been applied according to the Ground calibration results which means: - temperature dependent offset calibration - temperature dependent sensitivity calibration - temperature dependent misalignment calibration Data are given in different coordinates, dependent on the calibration LEVEL. LEVEL_F : averaged data in s/c-coordinates Source of these data are LEVEL_B data. Bad vectors have been removed. Any s/c caused residual magnetic fields are not eliminated. The ground temperature model for the sensor calibration has been improved (expanded for a wider temperature range down to - 130 deg C) using long term temperature model obtained from flight data. The data are sorted by the sensor (OB: outboard sensor, IB: inboard sensor)and the measurement mode (M1..M6) and average interval (A<n>, where n denotes the average interval in seconds). Data can uniquely be identified by their file names. Averaging means calculating a mean value of of the specified interval in time domain. It does not mean any mixing of data from the OB and IB sensor. Normally the OB is the Primary (Pri) and the IB is the Secondary (Sec) sensor. However, this order can be toggled by TCs. This feature has been tested especially during the commissioning phases. In cases where the PRIMARY and SECONDARY sensor were toggled the individual data files (OB/IB) will contain data measured with different sampling rates according to the actual sampling rates of the PRIMARY and SECONDARY sensors. Refer to the MODE DESCRIPTION table below. The actual sampling rate is the only indicator showing which sensor is the primary and which is the secondary one. REMARK: ======= Due to strong magnetic disturbance by the ORBITER the magnetic field data are influenced by s/c generated magnetic fields. The source of these disturbance is manifold: - transient currents flowing on the spacecraft - Heater pulses These rectangular disturbances are in the order of 1-2 nTpp, depending on the heaters and occur with the PWM periods of the heaters (usually a few seconds up to minutes) - Thruster related magnetic field disturbances These signatures are in the order of 3 nTpp and occur during Wheel off loading (WOL) maneuvres and Orbit correction maneuvres (OCM). Endurance is usually up to 20 minutes. Additional spikes occur during OCMs with periods of 625 mHz and amplitudes of 6 nTpp and about 200ms width. - Reaction wheel (RW) signatures The four rotating s/c RWs are causing four different sinusoidal disturbances with usually slowly varying frequencies in the range of 1-10 Hz with amplitudes of about 3nTpp. The 'tilted traces' of these signatures can clearly be seen in the dynamic spectra and can easily be distinguished from external magnetic field variations. - Interference by the RPC-LAP instrument There are times where the LAP instrument can be seen in the magnetic field spectrum. The disturbance occurs at a constant frequnecy of either 3.2 Hz or 3.6 Hz with an amplitude of about 1 nT. - etc. Due to the complexity of these circumstances a proper data cleaning is an ongoing task. Thus the data of the present dataset still contain the mentioned disturbance signatures. Therefore, any use of the data for scientific research has to be done under consideration of these disturbances. REMARK ON TIMING ================ It turned out that the OB data are shifted against IB data and also against ROMAP data by 1s. This behavior has not been corrected in the data. Therefore, for proper comparison in high resolution analyses, a time shift of 1s should be subtracted from all OB data. Alternatively OB data can be left as they are and a 1s shift had to be added to the IB and ROMAP data. Mode description: ================= MODE SAMPLE RATE PACKET PERIOD PACKET LENGTH VECTOR RATE Minimum Mode M1 1/32 Hz 1024 s 32 Pri Vec 0.03125 vec/s 1 Sec Vec 0.000976 vec/s Normal Mode M2 1 Hz 32 s 32 Pri Vec 1 vec/s 1 Sec Vec 0.03125 vec/s Burst Mode M3 20 Hz 16 s 320 Pri Vec 20 vec/s 16 Sec Vec 1 vec/s Medium Mode M4 5 Hz 32 s 160 Pri Vec 5 vec/s 1 Sec Vec 0.03125 vec/s Low Mode M5 0.25 Hz 128 s 32 Pri Vec 0.25 vec/s 1 Sec Vec 0.007812 vec/s Test Mode M6 20 Hz 16 s 320 Pri Vec 20 vec/s 1 Sec Vec 0.0625 vec/s HK Mode 32 s 8 words 0.03125 vec/s The HK mode contains coarse magnetic field information, measured by the primary sensor with 16 bit resolution only. These data will not be calibrated and are not used for any purpose. FILENAME CONVENTION & Mode Coding =================================== Due to operational constraints it might happen that the instrument mode or the primary sensor has to be switched during a specific observation. The actual mode and the primary sensor of the instrument can easily be identified by analyzing the filename of the actual data files. The complete filename convention is listed in the EAICD, chapter 3.1.4. The filenames for RESAMPLED averaged data (CLF,CLG) are coded as follows: <inst> <begin of observation>_<level>_<sensor>_A<average>.<ext> RPCMAG yymmdd CLF IB A60 LBL CLG OB TAB Example: RPCMAG040528_CLG_OB_A20.LBL RPCMAG040528_CLG_OB_A20.TAB Average denotes the time interval for one average period in seconds. The filenames for RESAMPLED Heater or Reaction Wheel influenced data (CLH) are coded as follows: <inst> <begin of observation>_<level>_<sensor>_<inst mode>.<ext> RPCMAG yymmddThhmm CLH IB M1..M6 LBL OB TAB Example: RPCMAG040528T1230_CLH_OB_M3.LBL RPCMAG040528T1230_CLH_OB_M3.TAB LEVEL Description, Science Data =============================== LEVEL_F : Calibrated data in s/c-coordinates Table content: Time (UTC), Time(OBT), Magnetic Field (Bx, By, Bz) [nT], Sensor Temperature [K], Quality Flags Geometry Information - Coordinate System ======================================== The geometry items SC_SUN_POSITION_VECTOR SC_TARGET_POSITION_VECTOR SC_TARGET_VELOCITY_VECTOR provided in the label of the data product are relative to the ECLIPJ2000 frame. This reference frame is built up by Ecliptic Coordinates related to Equinox of Epoch J2000. Orientation: X: Pointing from SUN to Vernal Equinox, Y: perpendicular to X in Ecliptic Plane, Z: Perpendicular to Ecliptic plane, pointing up The items SUB_SPACECRAFT_LATITUDE SUB_SPACECRAFT_LONGITUDE are given in the PLANETOCENTRIC coordinate system. All these geometry parameters are computed at time t=START_TIME. Distances are given in km, angles in degrees. Version Information =================== The actual version of this dataset is V6.0, the first being archived.
These data are available on-line from the Planetary Data System (PDS) at:
https://pdssbn.astro.umd.edu/holdings/ro-c-rpcmag-4-ext1-resampled-v6.0/
Questions and comments about this data collection can be directed to: Dr. David R. Williams
Name | Role | Original Affiliation | |
---|---|---|---|
Prof. Karl-Heinz Glassmeier | Data Provider | Technische Universitat Braunschweig | kh.glassmeier@tu-braunschweig.de |
Dr. Ingo Richter | General Contact | Technische Universitat Braunschweig | i.richter@tu-bs.de |