Developed specifically as a position updating guidance system for missile applications, the feasibility of the Range Only Correlation System (ROCS) was established by computer simulation in 1969-1970 and flight testing in 1975-1977. ROCS consists of a conventional radar sensor and a digital processor; it establishes the actual location of a vehicle flying at either high or low altitude extremes and over a wide variety of terrain characteristics. For high altitude applications this system derives position information by sequentially comparing three or more independent radar range returns with prestored range references. For low altitude applications vertical position information is obtained with the system operating in an altimeter mode, while horizontal position information is derived by comparing two independent radar range returns with references. The general features of this position updating system are presented. This includes a description of the radar sensor, the digital processor, the reference data, the performance characteristics, and lastly, the objectives of the current flight test program.
C. G. Reed,
J. M. Kohn,
"The Range Only Correlation System", Proc. SPIE 0238, Image Processing for Missile Guidance, (23 December 1980); doi: 10.1117/12.959131; https://doi.org/10.1117/12.959131