Analysis of Spacecraft Charging and Geophysical Data Bases

This report documents investigations and computer programs developed for analysis of spacecraft charging and geophysical data bases. Spacecraft charging studies were performed using the NASCAP and associated MATCHG programs. Simple as well as complex SCATHA models were configured, and results for materials charging, rotation effects, potential monitor, and gun events in different environments were simulated. NASCAP verification and validation to date is summarized. Ion composition modeling was initiated using mass spectrometer measurements of N+, O+, N2+, NO+ and O2+ ion densities on board the S3-1 satellite. Procedures for partitioning, editing, averaging, and analyzing the geophysical data base are described. Graphical presentation techniques are used extensively, and provide a basis for subsequent modeling. An interactive graphics program (SUATEK) was developed to satisfy requirements for flexible data presentation and evaluation by researchers. Data manipulation, editing, as well as selective plotting features are available, and operate on a standardized data base format. On-line Tektronix and Off-line Pen-and-Ink, Microfiche, or Tektronix compatibility is retained as far as possible.