VO1/VO2 MARS VISUAL IMAGING SUBSYSTEM EXPERIMENT DATA RECORD

After the digital data were transmitted to Earth and received at the Jet Propulsion Laboratory, they were subject to a variety of processes to produce the final digital tapes and photoproducts. The first step was to strip out all the non-video data and produce a System Data Record (SDR). This was compiled into video format, and an Experiment Data Record (EDR) was produced. The EDR data consist of unprocessed (raw) instrument data. Substantial processing is required to reconstruct each image owing to the unique manner in which data were transmitted to earth. Images were initially recorded on 7-track magnetic tape recorders on the spacecraft. Each raw data frame retrieved from the tracking station thus contains every seventh pixel arranged in either increasing or decreasing order. Image data reconstructed from these raw data frames by the Mission Test Imaging System (MTIS) form the EDR digital archive tape.