HIGH RANGE RESOLUTION COHERENT RADAR
ARMY ELECTRONICS LABS FORT MONMOUTH NJ
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An experimental coherent radar was assembled to investigate the value of high range resolution, without comparable azimuthal resolution, in differentiating between natural targets and man-made targets. A pulsed varactor diode in a microwave switch was used to modulate the output of a CW klystron. The peak power output was about 100 milliwatts. The best range resolution obtained was about three feet. Since the system used coherent detection, any target motion appeared quite clearly on the A-scope presentation. A distinct difference could be seen between the return from a steadily moving target such as a vehicle and the return from an irregularly moving target such as a tree branch or foliage swaying in the wind. A range resolution of 15 feet was found to be insufficient to show any clear differences between a walking man and a moving vehicle. With a six-foot range resolution, however, the return from a moving vehicle began to show more than one peak. With the three-foot resolution, a vehicle might show as many as four or five peaks. An intensity- modulated raster display was used for part of the tests. This type of display, which presented the relative phases of the separate returns from a target where the resolution was fine enough to produce more than one return, also indicated the possibility of showing whether a slowly-moving target was approaching or receding. The use of different types of vehicles at varying aspects is recommended for further evaluation of the high range resolution technique. Reduction in equipment size and weight to provide portability is also recommended.
- Active and Passive Radar Detection and Equipment