JAMMER TRACKING WITH FREQUENCY-SCANNED RADARS BY LOBE COMPARISON
Abstract
Frequency-scanned array radars may be preferred to phase-scanned radars because they tend to be cheaper and simpler. When conventional frequency- scanned radars are used to measure the angular position of jammers, however, large errors can result. These can be eliminated with the lobe-comparison technique. The response of a frequency-scanned array to a jammer can be compared with that of a filter whose characteristics depend on the angle of signal arrival. Variations of jammer power with frequency and time can distort the array output spectrum to cause measurement errors. With lobe comparison, the array is divided to produce two slightly different frequency response functions (equivalent to two beams, like those in a monopulse radar). The angle of signal arrival is estimated by comparing the response of the two arrays in a narrow frequency band. If the band is sufficiently narrow, measurement error can be reduced to a satisfactory level with no penalty in noise performance. In practice, a bandwidth about one-fifth that of the radar signal reduces error to less than the usual fixed-error limit of the array. Lobe comparison can be applied to frequency-scanned radars, including phase-frequency-scanned arrays, with only a small increase in cost and complexity. The improved performance in measuring jammer angular position compares well with that of phase-scanned arrays.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1967
- Accession Number
- AD0826284
Entities
People
- G. R. Curry