Method for increasing the resolution and accuracy of radar angular measurements based on sequential spatio-temporal processing of received signals

Abstract

Introduction: Increasing requirements for the location accuracy of radar stations, along with the minimization of their structural changes, necessitates the use of special mathematical algorithms for digital signal processing. The use of such algorithms makes it possible to increase the resolution of a radar station up to a superresolution exceeding the Rayleigh resolution, without any constructive modification of the antenna systems. The existing superresolution algorithms require a large computational cost and a long signal accumulation time. Purpose: Obtaining superresolution in the angular coordinates of a linear antenna array due to digital synthesis of longitudinal flat aperture in real time by digital methods. Methods: An amplitude-phase distribution is formed on the elements of a linear lattice of the data array. On this base, a longitudinal flat aperture is synthesized using digital modeling algorithms for “virtual re-emission” of the received signals. Results: Based on the proposed method of synthesizing a linear antenna array aperture in the longitudinal plane, an algorithm was developed for estimating the increase in the angular resolution of the linear antenna array. Computer simulation of the resulting lattice was performed, and its radiation pattern was built. The dependence was analyzed of the angular resolution on the phasing direction and on the synthesis interval when using this method. Quantitative assessments were carried out by the comparison between the obtained angular resolution and a potentially possible one determined by the Rayleigh criterion. The resolution in angular coordinates when using this method increases by 1.5 times. Thus, the proposed method allows you to increase the angular resolution of a radar station without any significant structural changes in the antenna array, using relatively simple algorithms. Practical relevance: The application of this method in radar stations, especially those operating in the short-wave range where increasing the size of the antenna array is a rather difficult task, will improve the radar measurement accuracy.