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 COMET ESCORT 3 Phase of
ROSETTA. Included are the following  sub-phases:



MTP0018 - STP0063 from 2015-06-30T23:25 to 2015-07-07T23:25
MTP0018 - STP0064 from 2015-07-07T23:25 to 2015-07-14T23:25
MTP0018 - STP0065 from 2015-07-14T23:25 to 2015-07-21T23:25
MTP0018 - STP0066 from 2015-07-21T23:25 to 2015-07-28T23:25

MTP0019 - STP0067 from 2015-07-28T23:25 to 2015-08-04T23:25
MTP0019 - STP0068 from 2015-08-04T23:25 to 2015-08-11T23:25
MTP0019 - STP0069 from 2015-08-11T23:25 to 2015-08-18T23:25
MTP0019 - STP0070 ITLS 2015-08-18T23:25 to 2015-08-25T23:25

MTP0020 - STP0071 from 2015-08-25T23:25 to 2015-09-01T23:25
MTP0020 - STP0072 from 2015-09-01T23:25 to 2015-09-08T23:25
MTP0020 - STP0073 from 2015-09-08T23:25 to 2015-09-15T23:25
MTP0020 - STP0074 from 2015-09-15T23:25 to 2015-09-22T23:25


MTP0021 - STP0075 from 2015-09-22T23:25 to 2015-09-29T23:25
MTP0021 - STP0076 from 2015-09-29T23:25 to 2015-10-06T23:25
MTP0021 - STP0077 from 2015-10-06T23:25 to 2015-10-13T23:25
MTP0021 - STP0078 from 2015-10-13T23:25 to 2015-10-20T23:25



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
 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 EDITED and CALIBRATED data are coded as follows:

  ___.
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:

  _.
RPCMAG         yymmddThhmm         HK      LBL
                                           TAB

Example: RPCMAG040528T1230_HK.LBL
         RPCMAG040528T1230_HK.TAB



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 first version of RPCMAG datasets being archived for this comet
phase and calibrtation level was level V6.0.

This data set has  the same structure as the
                         former RPCMAG datasets obtained between 2004
                         and 2011.
                         Those datasets have been reviewed by two
                         independent teams in Spring 2012. After these
                         reviews the datasets had been accepted by
                         the Planetary Science Archive(PSA) of the ESA
                         and by the Planetary Data System(PDS) of NASA
                         for long-term archiving.
                         A third review by european and US peers
                         took place in February 2016 and a fourth
                         review happened in October 2017.RPCMAG passed
                         these reviews very well with with only some
                         minor and editorial issues. All the required
                         updates and changes due to this review were
                         implemented in the present dataset.
                         All data have been processed  on best effort
                         basis according to  the procedures described
                         in RO-IGEP-TR0028: ''Step by Step Calibration
                         Procedure''. Quality flags are attached for
                         CALIBRATED and RESAMPLED data as described
                         in the EAICD RO-IGEP-TR0009. Both documents
                         are available in the DOCUMENT directory.