PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM ^TEXT = "INFO.TXT" OBJECT = TEXT PUBLICATION_DATE = 1996-01-01 NOTE = "INFO.TXT describes the data." END_OBJECT = TEXT END Galileo Magnetometer Cruise Data(RTN coordinates) Mission Phase Name: Earth-Venus cruise,Venus-Earth cruise, Earth-Earth cruise,Earth-Jupiter Cruise Usefule Files: INFO.TXT Describes the data .DAT data files .LBL PDS label files which describe data files MAGDATA.FMT PDS format file which describes the structure of the data DATASET.TXT PDS format file which describes the dataset The majority of the processing of the interplanetary cruise data is done onboard the spacecraft. The following procedures take place onboard. 1) Data is recursively filtered and is decimated a to 4.5 vectors/second 2) Sensor zero levels are subtracted and gains are applied 3) Data is transformed from a sensor coordinate system to a spacecraft coordinate system using an orthogonality matrix 4) Data are decimated again to 2/3 second resolution 5) Data are despun into inertial rotor coordinates 6) A recursive filter is applied and data are decimated to a variable resolution Once the data is on the ground there is very little that can be done to improve the onboard processing because of the heavy filtering and decimation. The following procedure is done on the ground. 1) Data is converted to nanoTesla 2) The zero level of the spin aligned sensor is corrected 3) Timing is set to account for a phase delay 4) Data are rotated to account for phase delay in Analog to Digital converter. 5) Data are rotated to RTN coordinates The data are stored as 5 ASCII files. The data are in the '.TAB' file. Each data file has a PDS label file (.LBL) which describes some of the physical properties of the data. There is a single format file (.FMT) which describes the columns of the data files. /-------------------------\ | D A T A | \-------------------------/ Columns in all data files: ===================================================== name type description ----------------------------------------------------- sc_clk char S/C clock counter given in the form rim:mod91:mod10:mod8 time char time S/C event time (UT) given in the form yyymmddT