Multi-Experiment Data

Description

This collection consists of data generated by four of the instruments on Ariel 4: the Langmuir probe, radio noise, VLF-ELF propagation, and low-energy protons and electrons (LEPEDEA) instruments. The data are binary and were originally written to magnetic tape on an ICL 1900 computer. Both low-speed (play-back of the on-board tape recorder) and high-speed (real-time recordings over the telemetry station) data are included. Approximately 90% of the originally archived data was high-speed.

Two types of files are present. The first is a file which contains information about the data as it existed on tape, including tape generation information, the number of files on the tape, and the year, day, and hour of the data in the first and last data files from that original tape. The second is a data file.

Each data file contains a sub-file header with time and satellite position information. The header is followed by time units which are four or two records long depending on whether the tape contains high-speed or low-speed data, respectively. The first record of each time unit contains universal and local solar times and ephemeris information. The next record (low speed tape) or the next three records (high-speed tape) contain the investigation data. All of the data from the four experiments are combined in one record. The final portion of each data file consists of two "Crib" (investigator's terminology) data records, containing low-speed investigation data, numerous error flags, and time.