Improving the efficiency of coherent-pulse radar under the impact of combined interferences

Abstract

To ensure the interference immunity of modern radars, two-stage space-time signal processing is used. However, under the simultaneous impact of active noise interference (jamming) and passive interference (clutter), the passive interference decorrelates the active component of the combined interference. Besides, modulation of clutter with weight coefficients for spatial signal processing destroys the temporal correlation of clutter. This significantly limits the interference immunity of coherent-pulse radars.The goal is to improve the efficiency of coherent-pulse radar under the impact of combined interferences.The method is implemented using the proposed methodology for estimating the distribution of passive interference in range in the elevation radar channels and using different methods of generating a classified training sample in order to adapt the weight coefficients of the spatial filter in different parts of the coverage area.Simulation results confirmed that the "on the fly" correlation analysis of signals in range in real time makes it possible to determine the time interval at which the passive interference is absent by the maximum value of the module of the inter-channel correlation coefficient in the lower part of the radar field of view. This allows you to create a classified training sample to adapt the weight coefficients of the spatial filter, generated only by active noise interference.The formation of a classified training sample excludes the modulation of passive interference acting in the compensation channel of the spatial filter. This can significantly increase the efficiency of detection of useful signals in the second stage of space-time filtering of signals in the radar. The use of a classified training sample (CTS) can significantly reduce the time of the transient process of adaptation of the weight coefficients of the spatial filter.