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NASA Space Science Data Coordinated Archive Header



Availability: Archived at NSSDC, accessible from elsewhere

Time span: 1989-12-31 to 1994-12-31


This description was generated automatically using input from the Planetary Data System.

Data Set Overview ================= This data set contains data acquired by the Galileo Magnetometer during the Interplanetary Cruise to Jupiter. The data are at varying resolution depending on the averaging constant applied to the instrument. The EDR files (Experimentor Data Record) were delivered to the Galileo Magnetometer Team by the Galileo project. The EDR files are given in IBM 370 binary representation and are stored in an extremely compact format. The structure of the EDR files is completely described in the documents GLL280 and GLL640. The pages pertinent to the MAG description have been scanned into bit map images (TIFF) that are stored in the /DOCUMENT directory off the root of this volume. Data Acquisition ================ The data for this dataset were acquired as part of the normal instrument calibration activities associated with the cruise to Jupiter. As such, the instrument was commonly configured in modes which required calibration even though they may not have been the optimal mode for science data acquisition. The Galileo magnetometer has 8 possible LRS acquisition configurations (modes). There are two sensor triads mounted 6.87 and 11.03 meters from the rotor spin axis (inboard and outboard) along the boom. Each of the sensor triads has two gain states (high and low). In addition, the sensor triads can be 'flipped' to move the spacecraft spin-axis aligned sensor into the spin plane and visa versa. Please see the instrument description for full details on the instrument, sensors, and geometries. The combinations of sensor, gain state, and flip direction form modes. ______________________________________________________________________ Mode Characteristics ______________________________________________________________________ Mode Name Acronym range quantization ______________________________________________________________________ Inboard, left, high range* ILHR +/- 16384 nT 8.0 nT Inboard, right, high range* IRHR +/- 16384 nT 8.0 nT Inboard, left, low range* ILLR +/- 512 nT 0.25 nT Inboard, right, low range* IRLR +/- 512 nT 0.25 nT Outboard, left, high range* ULHR +/- 512 nT 0.25 nT Outboard, right, high range* URHR +/- 512 nT 0.25 nT Outboard, left, low range* ULLR +/- 32 nT 0.008 nT Outboard, right, low range* URLR +/- 32 nT 0.008 nT __________________________________________ Summary of Mode Changes __________________________________________ s/c clock date/time mode __________________________________________ 00104651:00:0 89-353/20:53 ULLR 00120107:00:0 89-364/17:21 URHR 00120117:00:0 89-364/17:31 IRHR 00120150:00:0 89-364/18:04 IRLR 00120178:00:0 89-364/18:33 ILLR 00120199:00:0 89-364/18:54 ILHR 00120209:00:0 89-364/19:04 URHR 00120231:00:0 89-364/19:26 URLR 00120283:00:0 89-364/20:19 ULLR 00120313:00:0 89-364/20:49 ULHR 00572976:00:0 90-040/03:00 ULHR 00572976:00:0 90-316/17:00 ULLR 00578673:00:0 90-320/17:00 URLR 00586204:00:0 90-325/23:55 URHR 00592915:00:0 90-330/17:01 ILLR 00597439:00:0 90-333/21:15 IRLR 00610156:00:0 90-342/19:33 IRHR 00610509:00:0 90-343/01:30 IRLR 00615701:00:0 90-346/17:00 URLR 00618550:00:0 90-348/17:00 URHR 00624261:00:0 90-352/17:15 ULHR 01072247:00:0 91-302/06:39 ULHR 01600269:00:0 92-308/00:48 ULLR 01605562:00:0 92-311/18:10 ILLR 01629549:00:0 92-328/14:14 IRLR 01632087:00:0 92-330/09:00 ULLR 01635479:00:0 92-332/18:23 URHR 01638675:00:0 92-335/00:01 URLR 01639786:00:0 92-335/18:45 IRLR 01639974:00:0 92-335/21:55 URLR 01640958:00:0 92-336/14:30 IRLR 01641285:00:0 92-336/20:40 URHR 01641351:00:0 92-336/21:07 IRHR 01641407:00:0 92-336/22:15 ILHR 01641465:00:0 92-336/23:02 URLR 01642481:00:0 92-337/16:22 ULHR 01644143:00:0 92-338/20:10 IRLR 01646048:00:0 92-340/04:16 ILLR 01649533:00:0 92-342/15:00 ULLR 01650524:00:0 92-343/07:42 ULHR 01650907:00:0 92-343/14:09 ILHR 01651026:00:0 92-343/16:10 ULHR 01656418:00:0 92-347/11:01 ILLR 01659057:00:0 92-349/07:30 ULLR 02035626:00:0 93-240/16:51 ULLR * range is the opposite of gain In addition to exercising the various instrument modes during the first earth encounters, numerous instrument calibration activities were performed. These include using both the internal and external calibration coils. Data corrupted by the use of the calibration coils or by the flipper motor have been removed from the raw data and kept in seperate calibration directories. Coordinate Systems =================== The EDR data are being archived in inertial rotor coordinates (IRC). This coordinate system has the Z axis along the rotor spin axis, positive away from the antenna and the X and Y axes lies in the rotor spin plane. In a crude sense, when the spacecraft is far from Earth, +X points south, normal to the ecliptic plane, positive Y lies in the ecliptic plane in the sense of Jupiter's orbital motion and positive Z is in the anti-earth direction. The spacecraft antenna (negative Z direction) is kept earthward pointing to about +/- 10 deg accuracy. Data Processing =============== The EDR files can be 'unbundled' using the software entitled 'unbundle_mro80' or 'unbundle_mro32'. The unbundling software will read in a raw EDR and convert the data to IEEE binary flatfiles (tables of data). Prior to doy 169 1993 the EDR's were delivered to the magnetometer team by the Galileo Project in a 32 byte format. The appropriate software to unbundle EDR data in a 32 byte format is 'unbundle_mro32'. After doy 169 1993 the Galileo Project delivered EDR data in an 80 byte format. The appropriate software to unbundle the 80 byte format data is 'unbundle_mro80'. More information regarding this software can be found in the SOFTWARE directory of this CDROM. Information regarding the structure and format of the EDR binary file is contained in the documents GLL280 and GLL640. The pages pertinent to the MAG description have been scanned into bit map images (TIFF) that are stored in the DOCUMENT directory off the root of this volume.

These data are available on-line from the Planetary Data System (PDS) at:

Alternate Names



  • Planetary Science: Fields and Particles

Additional Information



Questions and comments about this data collection can be directed to: Dr. Edwin V. Bell, II



NameRoleOriginal AffiliationE-mail
Dr. Margaret Galland KivelsonData ProviderUniversity of California, Los
Dr. Margaret Galland KivelsonGeneral ContactUniversity of California, Los
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