Dataset OverviewThis dataset contains resampled magnetometer data from the Pioneer VenusOrbiter spacecraft beginning with orbit 3602 (Oct 16, 1988) and continuinguntil the orbiter was lost in the Venusian atmosphere (orbit 5055,Oct 7, 1992). The dataset differs from the 2 spin period averaged mag datasetfrom the previous orbits due to an anomaly in the multiplexor that controlledthe sampling of the magnetometer sensors. During orbit 3602, and for theremainder of the mission, the spacecraft downlink contained magnetometerdata from only the P sensor. The P sensor is the sensor which is aligned withthe spacecraft spin axis, nominally in the direction of the ecliptic normal.Version 2.0 of this data set includes new versions of some of the dataproducts. The ancillary engineering (ENGR) were regeneratedsetting bad data to flag values. The original, unflagged data valuesare available in the binary version of the same data.After the anomaly was first detected, the magnetometer team made asubstantial effort to recover the average magnetic field vector using thesingle sensor data. Since the sensor is not perfectly aligned with thespacecraftspin axis, a small amount of spin modulation is present in thesensor data. In theory, the amplitude of the spin plane field can bedetermined from the amplitude of the spin modulation and knowledge of thetrue sensor mounting geometry. In practice, this turned out to be a verydifficult task because the spin axis of the spacecraft is not sufficientlyconstant in body-fixed coordinates.Data Processing and SamplingThis dataset has been calibrated to account for gains only.The data are given in units of nanoTesla. The data have beenderived from the high resolution dataset PVO-V-OMAG-3-P-SENSOR-V1.0by resampling. These data have been averaged over two spin period intervalson one spin period centers. The time tag given to each record is the projectassigned time value for the spin period (UADS time tag).The dataset contains the following columns:Column Description ___________________________________________________________________________UT S/C event time (UT) of the sample Bz-SC Calibrated/Averaged value of S/C coord. Z component of B Var-Bz The variance of Bz-sc over the two spin period interval Bn The magnetic field magnitude |B|. Ancillary Products Other datasets on the CD-ROM are the Ephemeris which contains spacecraftposition in Venus Solar Orbital coordinates, spacecraft altitude, solarzenith angle, Venus centered longitude and latitude, spacecraft spin axiscomponents, celestial longitude and latitude of the spacecraft, celestiallongitude of the earth, and the Sun-spacecraft range. Other ancillary datasets are the: 1) phase and offset which contains thephase amplitude of sun synchronous modulation of the 4 signals (E100, E730,E5.4 and E30K), and offsets of the G sensor. 2) The engineering dataset whichcontains temperatures, magnetometer modes, magnetometer sample format,magnetometer spin average select, telemetry data format, telemetry bit rate,spacecraft spin period, pulse time, the difference between the Sun pulse timeand the Rip pulse time, and the pulse time flag.References: Russell, C.T., R.C. Snare, J.D. Means and R.C. Elphic, 'Pioneer Venus Orbiter Fluxgate Magnetometer', IEEE Trans. Geo. Elec., vol. GE 18, no. 1 p. 32, 1980.

These data have been reprocessed several times during the courseof the mission. Each successive reprocessing has eliminated someof the problems found in earlier version of the data. Please bringto the attention of the original investigator any suspicious sectionof data. No zero level correction has been applied to the data.