DE 2 Vector Electric Field Instrument, VEFI, Magnetometer, MAG-B, Merged Magnetic and Electric Field Parameters, 62 ms Data

This Dynamics Explorer 2, DE 2, data set is a combination of the Vector Electric Field Instrument, VEFI, and Magnetometer-B, MAGB, high resolution data sets in spacecraft, SC, coordinates submitted to NSSDC. The following orbit-altitude, OA, parameters have been added to the data set:* 1) Model magnetic field, SC coordinates* 2) Satellite altitude* 3) Geographic latitude and longitude* 4) Magnetic local time* 5) Invariant latitudeThe VEFI data set is described in the file VEFIVOLDESC.SFD and the MAGB data set is described in the file MAGBVOLDESC.SFD, these files are portions of the Standard Format Data Unit, SFDU, metadata files submitted with the VEFI and MAGB data to NSSDC and are included in each volume of this data set. This data set consists of daily files from 1981-08-15, day of year 227, to 1983-02-16, day of year 47. Each file contains all the data available for a given day. During the merging of the data sets it was found that although VEFI and MAGB should cover the same time spans, they do not, due perhaps to the fact that the original MAGB high resolution data set was created on the DE Sigma-9 in Sigma-9 format by using the DE telemetry tapes, while the VEFI high resolution data set was created on the DE MicroVAX system using the DE telemetry data base on optical disk. In order to keep the largest amount of data possible, the merged data set includes all the available VEFI and MAGB data, for those times when VEFI data was available but MAGB was not, 6.54% of the time spanned by this data product, a fill value of 9999999. was given to the MAGB data. Likewise, for those times when MAGB data was available but VEFI was not, 6.87% of the time, the fill value was assigned to the VEFI data. Times for which both VEFI and MAGB data were fill values in the original data sets were not included in the merged data set. There were also times when certain OA parameters were fill values in the OA data base and they are therefore also fill values in this merged data set. The model magnetic field had fill values for 8.55% of the data. Statistics were not kept for the other OA parameters. Each daily file contains a record per measurement. The total number of records in each file varies depending on the amount of data available for a given day.The DE 2 spacecraft, which was the low-altitude mission component, complemented the high-altitude mission DE 1 spacecraft and was placed into an orbit with a perigee sufficiently low to permit measurements of neutral composition, temperature, and wind. The apogee was high enough to permit measurements above the interaction regions of suprathermal ions, and also plasma flow measurements at the feet of the magnetospheric field lines. The general form of the spacecraft was a short polygon 137 cm in diameter and 115 cm high. The triaxial antennas were 23 m tip-to-tip. One 6 m boom was provided for remote measurements. The spacecraft weight was 403 kg. Power was supplied by a solar cell array, which charged two 6 ampere-hour nickel-cadmium batteries. The spacecraft was three-axis stabilized with the yaw axis aligned toward the center of the Earth to within 1°. The spin axis was normal to the orbit plane within 1° with a spin rate of one revolution per orbit. A single-axis scan platform was included in order to mount the low-altitude plasma instrument (ID: 81-070B-08). The platform rotated about the spin axis. A pulse code modulation telemetry data system was used that operated in real time or in a tape recorder mode. Data were acquired on a science-problem-oriented basis, with closely coordinated operations of the various instruments, both satellites, and supportive experiments. Measurements were temporarily stored on tape recorders before transmission at an 8:1 playback-to-record ratio. Since commands were also stored in a command memory unit, spacecraft operations were not real time. Additional details can be found in R.A. Hoffman et al., Space Sci. Instrum., 5(4), 349, 1981. DE-2 reentered the atmosphere on February 19, 1983. A triaxial fluxgate magnetometer onboard DE 2, MAG-B, similar to one on board DE 1 (ID: 81-070A-01), was used to obtain the magnetic field data needed to study the magnetosphere-ionosphere-atmosphere coupling.The primary objectives of this investigation were to measure field aligned currents in the auroral oval and over the polar cap at two different altitudes using the two spacecraft, and to correlate these measurements with observations of electric fields, plasma waves, suprathermal particles, thermal particles, and auroral images obtained from investigation (ID: 81-070A-03). The magnetometer had digital compensation of the ambient field in 8000 nT increments. The instrument incorporated its own 12-bit analog-to-digital, A/D, converter, a 4-bit digital compensation register for each axis, and a system control that generated a 48-bit data word consisting of a 16-bit representation of the field measured along each of three magnetometer axes. Track and hold