RADAR ELEVATION ANGLES MEASUREMENTS OF LOW-ALTITUDE TARGETS OVER THE SEA BY ROOT-MUSIC METHOD UNDER INTERFERENCE FROM MULTIPATH AND THERMAL NOISE ОF DIRECTION FINDER

Abstract

The work is devoted to improvement of the accuracy of radar measurements of elevation angles of low-altitude targets above sea level when using the root-MUSIC, which is considered by experts as one of the means to solve this problem. Unlike previous studies, which take into account the multipath only, in this study the clutter is complicated by thermal noise of radar. This allows to evaluate the capabilities of the method and provide guidance on its application in the conditions close to reality. The study was carried out by computer simulation. It covered various sea states at which the conditions from specula to strong diffuse reflection were complied. In the simulation a wide range of signal/noise ratio was used. The main focus was the study of effects on measurement errors of a priori parameters of the method: the signal subspace dimension and the order of autocorrelation matrix of signals received by a multi-element antenna array. The recommendations of their choice, allowing to minimize the errors of elevation measurement in different conditions, have been developed. The results of the study extend the knowledge of how to improve the methods for measuring the target elevation angle above the sea.

Keywords

• computer simulation
• diffuse reflection
• elevation angle measurement
• low altitude target
• root-music
• specula reflection
• thermal noise