The communication system considerations of the Apollo space program limits the bandwidth available for TV signals to 0.5 MHz. Consequently, the Apollo black-and-white TV cameras operate at slow scan rates. The Command Module camera operates at ten frames/s and the Lunar Surveying camera produces one frame in 1.6 s. Both cameras are non-interlaced. The signals as received on the ground are not compatible with the standard broadcast rates, and scan conversion is required to convert to standard EIA format video signals suitable for transmission over commercial broadcast networks. The scan converter primarily consists of a kinescope which displays the slow-scan video, a vidicon camera which stores and converts the information to broadcast field and line rates, and a magnetic disc recorder which stores and repeatedly plays back the broadcast video. A detailed discussion of the various features and performance of the scan converter is presented, including incorporated image-enhancement techniques, pictures through the system, comments on actual performance and potential for improvement.
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