Digital Color Tv Telemetry

In most of the initial applications of digital TV telemetry the video source signal is monochrome (typically RS-170 standard). However color TV is now employed extensively in many of the government test ranges, and it is likely that it will be required to digitally transmit the NTSC color TV signal for security and other reasons. It is also likely that the bit rates which will be employed for this transmission will range from 1 to 20 mbps depending upon the application. This paper presents the general issues involved in digitizing color TV signals, describes alternative color coding techniques, compares these alternatives, and describes one particularly promising approach in detail. Alternative coding techniques that will be discussed and analyzed include direct coding of the composite NTSC signal as well as several component coding concepts Y, I, Q; Y, R-Y, B-Y; and the transmission of chroma lines on an alternating basis. Specific techniques for multiplexing the digitized color component signals will be presented. It is desirable that the color coding technique be an incremental expansion relative to existing monochrome coding concepts. One particular technique which shows promise of meeting this objective is presented and discussed.