Data Set Overview : Version 1.1 ----------- This version 1.1 data set replaces the version 1.0 data set (DATA_SET_ID : VG2-J-MAG-4-1.92SEC) previously archived with the PDS. Changes to this version include the addition of data columns not included in version 1.0, the modification of time format and flag values, and upgrade of associated labels and catalog templates to PDS version 3.4. Data Set Description -------------------- This data set includes Voyager 2 Jupiter encounter magnetometer data from the Low Field Magnetometer (LFM) resampled at a 1.92 second sample rate from the 60 msec instrument sampling rate. Data coverage begins in the solar wind and continues until at least the first magnetopause crossing. The data are given in Jovicentric System III (1965) right handed coordinates. The data set is composed of the following columns: 1) time - UT of the sample in the format yyyy-mm-ddThh:mm:ss.sssZ, 2) spacecraft clock values (m65536:mod60:fds_line), 3) mag_id - magnetometer id (1 : LFM, 2 : HFM), 4) Br - radial (Jupiter to spacecraft) B-field component, 5) Btheta - North/South (system III) B-field component (positive southward), 6) Bphi - azimuthal (system III) B-field component (positive eastward), 7) Bmag - magnitude of the averaged magnetic field components, 8) avg_Bmag - average of the magnetic field magnitudes, 9) delta - magnetic latitude : arcsin(Btheta/Bmag), 10) lambda - longitude : 180. - atan(Bphi/-Br), 11-13) rms_br, rms_bt, and rms_bn - rms vectors, 14) npts - number of points in average. All magnetic field observations are measured in nanoTesla. All of the magnetic field data are calibrated (see the instrument calibration description for more details). The Jupiter System III coordinate system is defined in [DESSLER1983] and the reference documents for this data set are: [NESSETAL1979A], [LEPPINGETAL1981], [CONNERNEYETAL1981], [BEHANNONETAL1981]. These data are provided in a conventional, right handed, spherical coordinate system with vectors R, Theta, and Phi. This system is sometimes referred to as System III (1965) right handed coordinates. The the magnetic field components are: BR - radial B-field component (along the Jupiter to spacecraft line) positive away from Jupiter BTHETA - North/South (system III) B-field component, positive southward BPHI - azimuthal (system III) B-field component, positive eastward Processing Level Id : 4 Software Flag : Y Processing Start Time : 1988-09-21 Parameters : Sampling Parameter Name : TIME Data Set Parameter Name : MAGNETIC FIELD VECTOR Sampling Parameter Resolution : 1.920000 Minimum Sampling Parameter : 19770820120000.000000 Maximum Sampling Parameter : UNK Sampling Parameter Interval : 1.920000 Minimum Available Sampling Int : 0.060000 Data Set Parameter Unit : NANOTESLA Noise Level : 0.006000 Sampling Parameter Unit : SECOND PARAMETER RESOLUTION DESCRIPTION NAME (UNITS) time 1.92 Sec time of the sample (UT) in the format yyyy-mm-ddThh:mm:ss.sssZ. The full sampling rate for the instrument is .06 +/- .006 sec. m65536, (counts) s/c clock mod 65536, mod 60 and mod60 and fds line fds_line mag_id n/a magnetometer ID magnetic (nT) measured parameter equaling the field magnetic field strength (e.g. in components nanoTeslas) along a particular axis (Br, Btheta, direction. Usually the three Bphi) orthogonal axis components are measured by three different sensors. magnetic (nT) derived parameter which combines the 3 field vector orthogonal magnetic field component (Bmag, avg_Bmag) measurements. delta n/a delta : arcsin(Btheta/Bmag) lambda n/a lambda : 180. - atan(Bphi/-Br) rms_Br, Pythagorean root mean square deviation rms_Bt, and of the component averages rms_Bp npts (counts) the number of data points in the current average Source Instrument Parameters : Instrument Host ID : VG2 Data Set Parameter Name : MAGNETIC FIELD VECTOR Instrument Parameter Name : MAGNETIC FIELD COMPONENT Important Instrument Parameters : 1 Instrument Host ID : VG2 Data Set Parameter Name : MAGNETIC FIELD VECTOR Instrument Parameter Name : WAVE MAGNETIC FIELD INTENSITY Important Instrument Parameters : 1 Processing : Processing History ------------------ Source Data Set ID : N/A Software : UNK Product Data Set ID : VG2-J-MAG-4-1.92SEC Ancillary Data : An ancillary data file containing the derived spacecraft magnetic field is provided with this data at a 48 second sample rate. These data provide zero level offsets used in the data processing. S/C field data is provided in spacecraft coordinates as follows: PARAMETER RESOLUTION DESCRIPTION NAME (UNITS) time 48 sec time in format yyyy-mm-ddThh:mm:ss.sssZ m65536 n/a s/c clock mod 65536 mod60 n/a s/c clock mod60 mag_id n/a magnetometer ID Bx (nT) spacecraft coords. X component By (nT) spacecraft coords. Y component Bz (nT) spacecraft coords. Z component Bmag (nT) total magnetic field strength rms_Bx (nT) rms Bx component rms_By (nT) rms By component rms_Bz (nT) rms Bz component npts (counts) number of points in average Data Coverage :Filename Records Start Stop-----------------------------------------------------------------------------Volume ID: VG_1502 S3_1_92S_I.TAB 576377 1979-07-05T00:00:47.269Z 1979-07-17T23:59:58.459Z S3_1_92S_II.TAB 556226 1979-07-18T00:00:00.379Z 1979-07-30T23:59:59.420ZS3_1_92S_III.TAB 431823 1979-07-31T00:00:01.340Z 1979-08-12T16:55:54.688Z

Confidence Level Overview : This data set contains some data gaps and spikes. The data set does contain a flag value which has been provided by the PI (Norman Ness) that indicates whether or not a particular record has been contaminated by software error or by spacecraft interference (a flag value of 1 indicates a bad value, 0 indicates that the record has either not been evaluated or is good). Some records that are obviously contaminated have not been flagged. The hourly summary data will show a contamination code and data quality code of 2 when data in the hour have not been flagged but are obviously in error and a contamination code of 1 when the hour contains flagged records.