PVO OMAG Data Bundle Readme Introduction ============ This document contains information pertaining to the PVO Magnetometer Data Bundle. This bundle includes vectors collected by the Pioneer Venus Orbiter (previously Pioneer 12) Magnetometer in ASCII and Original Binary forms. The data are provided in high resolution spacecraft coordinates, high resolution spacecraft coordinates averaged over 24 seconds on 12 second centers, high resolution spacecraft coordinates and high resolution spacecraft coordinates averaged over 24 seconds acquired after the multiplexer anomaly that allowed data from only a single sensor (P-sensor) to be returned to the ground. It also includes instrument status information. This bundle is organized into several collections, including: PVO Magnetic-Field VSO and Spacecraft Coords. High-Res Collections (urn:nasa:pds:pvo-omag-cal:data-sc-highres-asc & urn:nasa:pds:pvo-omag-cal:data-sc-highres-bin), PVO Magnetic-Field VSO abd Spacecraft Coords. 24 Sec. Avgs. Collections (urn:nasa:pds:pvo-omag-cal:data-sc-24s-asc & urn:nasa:pds:pvo-omag-cal:data-sc-24s-bin), PVO MAG Calibrated P-Sensor High-Res Collections (urn:nasa:pds:pvo-omag-cal:data-sc-highres-asc & urn:nasa:pds:pvo-omag-cal:data-sc-highres-bin), PVO Venus MAG Resampled P-Sensor 24 Sec Avgs Collections (urn:nasa:pds:pvo-omag-cal:data-psens-24s-asc & urn:nasa:pds:pvo-omag-cal:data-psens-24s-bin), PVO OMAG Instrument Status Collections (urn:nasa:pds:pvo-omag-cal:data-anc-inststat-asc & urn:nasa:pds:pvo-omag-cal:data-anc-inststat-bin), and document. PDS4 documentation is all XML. There is an XML label for every product in the archive. PVO Magnetic-Field VSO and Spacecraft Coords. High-res Collections ========================================================== In one format, apoapsis B, the magnetometer can be commanded to return 3 vectors per minor frame. In most others it transmits one vector per minor frame. In one format, periapsis E, it has no words in a minor frame. At very low sampling rates at which time the sine wave due to spacecraft spin could not be resolved. The magnetometer values are despun, and averaged on board using a Walsh transform (square wave) in phase and in quadiatune with the sun. PVO Magnetic-Field VSO and Spacecraft Coords. 24 Sec. Avgs. Collections =============================================================== The data are provided in spacecraft coordinates whose system has it Z axis antiparallel to the spacecraft spin axis during orbit. This choice maintained the Z axis along roughly the Earth's ecliptic north pole. Late in the mission when it was believed that the shadowing of the solar panels by the booms was causing a problem, the spin axis was moved to the pole of the Venus orbital plane. PVO MAG Calibrated P-Sensor High-Res Collections ===================================================== This collection includes high resolution data acquired after the multiplexer anomaly that allowed data from only a single sensor (P-sensor) to be returned to the ground (orbits 3602-5055, 1988-10-15 to 1992-10-08). PVO Venus MAG Resampled P-Sensor 24 Sec Avgs Collections ======================================================== This collection includes resampled magnetometer data from the Pioneer Venus Orbiter spacecraft beginning with orbit 3602 (Oct 16, 1988) and continuing until the orbiter was lost in the Venusian atmosphere (orbit 5055, Oct 7, 1992). The dataset differs from the 2 spin period averaged mag dataset from the previous orbits due to an anomaly in the multiplexor that controlled the sampling of the magnetometer sensors. During orbit 3602, and for the remainder of the mission, the spacecraft downlink contained magnetometer data from only the P sensor. The P sensor is the sensor which is aligned with the spacecraft spin axis, nominally in the direction of the ecliptic normal. PVO OMAG Instrument Status Collections ====================================== This collection contains data which maybe used to assess the quality of the OMAG science data. The data contains information of interest to the engineer. It includes instrument status information. Every effort has been made to insure that the data are of the best quality available. However, users are encouraged to verify the correctness of the data prior to submitting any publications or other work based on these data and report any issues to PDS/PPI. This is a PDS4 archive of the following PDS data sets: PVO-V-OMAG-3--SCCOORDS-HIRES-2.0 (https://doi.org/10.17189/ktv3-t936), PVO-V-OMAG-3-P-SENSOR-HIRES-2.0 (https://doi.org/10.17189/awd9-v380), PVO-V-OMAG-4--SCCOORDS-24SEC-2.0 (https://doi.org/10.17189/6skx-3c53), PVO-V-OMAG-4-P-SENSOR-24SEC-2.0 (https://doi.org/10.17189/hkep-8z69). These data sets were originally archived under PDS3 in the following volumes: PVO-V-OMAG-3--SCCOORDS-HIRES-2.0 and PVO-V-OMAG-4--SCCOORDS-24SEC-2.0 in PV01_0001 to PV01_0058 PVO-V-OMAG-3-P-SENSOR-HIRES-2.0 and PVO-V-OMAG-4-P-SENSOR-24SEC-2.0 in PV01_0059 to PV01_0068 Instrument Status data was found in the above PDS data sets and the volumes PV01_0001 to PV01_0058 Under the PDS3 standard all archives were self contained and could in principle be stored in a single file system (disk, CD-ROM, etc.). PDS4 takes advantage of the network capabilities that allow archives to be distributed. As a result, some of the documents and metadata previously stored in the PDS3 catalog files are no longer maintained locally, but are maintained in a central repository. Those files are referenced by unique PDS logical identifiers that are included in the document collection inventory. Errata ====== Errors were found when validating PVO Magnetomer Data. For data-sc-highres-asc, data files were regenerated to correct errors in the BZ_VSO values. For the data-sc-24s-asc, data files were regenerated since Bt values calculated from the VSO vectors did not match the Bt values already included with the ASCII data. For data-anc-inststat-asc, data files were regenerated, setting bad data to flag values. More detailed information can be found within the errata.txt file in the document collection (urn:nasa:pds:pvo-omag-cal:document:errata). Contacts ======== For questions or problems regarding this bundle, please contact the PDS Planetary Plasma Interactions Node: Email pds_operator@igpp.ucla.edu