A data formatter and control unit for the Seasat-A synthetic aperture radar ground support network

The Applied Physics Laboratory has developed special ground station equipment for NASA that recovers the video radar returns and timing reference signals from the Seasat-A spacecraft synthetic aperture radar (SAR), digitizes the video data, and combines video and engineering data into a format compatible with a high-speed digital tape recorder. This paper describes the design and implementation of the SAR data formatter, which performs the video digitizing and data formatting functions for tape recording, and the formatter control unit, which uses stored commands from the station control center to direct operation of a special downlink demodulator during satellite passes.