Advanced mathematical and computational techniques for simulation of the display produced by an airborne radar over a wide range of flight regimes and radar equipments. Incorporation of a small-scale, general-purpose digital computer, in combination with specialized methods of efficient terrain representation, to control special-purpose analog function generation circuits. Resulting waveform, simulated in real time under operator control without necessity for preprogramming of flight path, is to be displayed for advanced radar training. (Author).

A study of the extent to which digital computing techniques may afford improved performance in the realtime simulation of airborne radars is reported. It is desired to reproduce the display presented by a scanning, groundmapping radar, having a range in the order of 200 miles and a resolution in the order of 60 points per mile. The simulated radar is mounted in an aircraft that flies at a maximu speed of Mach 3 at any altitude up to 10 miles, the flight plan not known to the simlator in advance. While a cursory examination of such requirements indicates that a straight-forward digital computer simulation of the display waveform would require exorbitant memory sizes and tremendous computational speeds, many factors can be used to advantage, in order to reduce the computational complexity to economically manageable proportions. Redundancy in the terrain itself implies that the height and reflectivity observed by the radar are not purely random functions; their consistency or predictability can be shown to significantly reduce the information-handling capacity of a simulator. (Author).

To generate input data with a 50-foot resolution and fifteen shades of gray for advanced high-resolution digital radar simulators, this research examined and defined data sources and processing techniques. Limited to the Continental United States and to unclassified information, the data sources included all known aerial mapping imagery and topographic maps. All existing image processing techniques and devices were examined to define their operating principles. This review led to the conclusion that adequate geometric information for radar simulation data could be extracted from the current data sources and that existing processing capabilities could be combined into a feasible automatic system. In related work, non-parametric three-dimensional resections were calculated on a digital computer, and mathematical concepts were developed to give a computer system the capability of interpreting the physical characteristics in photos by using cues as done by a trained photo interpreter. (Author).