NSSDCA ID: PSSB-00638
Availability: Archived at NSSDC, accessible from elsewhere
This description was generated automatically using input from the Planetary Data System.
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 PRELANDING Phase of ROSETTA. Included are the following sub-phases: -the Rendezvous Manoeuvre 2 (RVM2) between January and September 2014 -the Post Hibernation Commissioning in March/April 2014 -the Near Comet Drift Phase (NCD) between March and July 2014 -the Far Approach Trajectory (FAT)between July and August 2014 -the Comet Characterization Phase (CC) between August and September -the Global Mapping Phase/Close Observation Phase (GMP/COP) between September and October 2014 -the Landing and First Science Sequence (LD/FSS) between October and November 2014 The several Landings of PHILAE happened on November 12, 2014. All magnetic field data are edited raw data. That means the data represent the 3 components of the magnetic field measured in counts of the used 20 bit ADC. Data are given in instrument coordinates. Neither any filtering nor any calibration has been applied to the data. Any s/c generated noise and s/c caused residual magnetic fields are not eliminated. The data are sorted by the sensor (OB: outboard sensor, IB: inboard sensor)and the measurement mode (M1..M6). They can uniquely be identified by their file names. 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 and by the LANDER Philae, 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 - Thruster related magnetic field - Reaction wheel signatures - 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.
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 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 for any purpose.
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 EDITED and CALIBRATED data are coded as follows: <inst> <begin of observation>_<level>_<sensor>_<inst mode>.<ext> RPCMAG yymmddThhmm RAW IB M1..M6 LBL CLA OB TAB CLB CLC Example: RPCMAG040528T1230_RAW_OB_M3.LBL RPCMAG040528T1230_RAW_OB_M3.TAB The filenames for Housekeeping data are coded as follows: <inst> <begin of observation>_<datatype>.<ext> RPCMAG yymmddThhmm HK LBL TAB Example: RPCMAG040528T1230_HK.LBL RPCMAG040528T1230_HK.TAB
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.
The first version of RPCMAG datasets being archived for the comet phase was V5.0. The actual version of this dataset is V6.0. The version number had to be increased due to changes in houskeeping data and quality flag changes.
These data are available on-line from the Planetary Data System (PDS) at:
http://pdssbn.astro.umd.edu/holdings/ro-ss-rpcmag-2-prl-raw-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 |