S.P. Barinov1, Y.I. Maevskii2, V.I. Sergeev3

1 JSC «Kaluga Scientific Research Radio Engineering Institute» (Zhukov of Kaluga Region, Russia)

2 JSC KRET (Moscow, Russia)

3 MESC «Zhukovsky–Gagarin Air Force Academy» (Voronezh, Russia)

Airborne synthesized aperture radars (SAR) are actively used in a wide range of challenges related to coordinate measurement of ground objects at the present time. A significant increase of consistency of SAR functioning in conditions of external intended interference that influences the main and side lobes of an antenna pattern (AP) of a SAR is achieved by the use of subsystems of adaptive spatial interference compensation (SIC) based on multi-channel receivers. Previous studies suggested variants of architecture of SIC subsystems on the basis of direct inversion of correlation matrix (CM) of processes at the output of a multi-channel receiving system on the basis of an algorithm with limitations and blocking; besides, previous studies dealt with issues of jam-resistance of SAR in conditions of external masking interference. With regard to the above, it was suggested that an-gular movements of the interference source in typical conditions of SAR functioning are insignificant and they do not substantially influence the quality of compensation. Along with this, aperture synthesizing is a time-taking process, and its duration can be from fractions to units of seconds. In such conditions, angular movements of an interference source (IS) in course of aperture synthesizing process affect the quality of interference compensation.

The purpose of this article is to develop the method of determination and estimation of rational (by the criterion of allowable level of suppression ratio reduction) values of time parameters of SIC SAR with consideration of IS angular movement. Two following tasks were done in the furtherance of this purpose: 1) analysis of special condition of SAR operation and determination of typical values of IS angular movement; 2) developing of method and estimation of SIC rational time parameters with consideration of dynamics of angular movement of IS located in the SAR AP side-lobe area. The decision of these tasks resulted in development of methods allowing to define rational (by the criterion of allowable level of interference compensation factor reduction) values of time parameters of SIC of SAR (sample accumulation time and period of sequence of counting of correlation matrix). Dependences of interference compensation ratio normalized to its maximum value on sample accumulation time at various periods of sequence of CM counting are found for typical conditions of SAR functioning. It is shown that effects of mutual influence of different limiting factors (accumulation time and sample volume) on the value of suppression ratio become apparent at values of the periods of sequence of counting equal to more than 10−3 s and at sample accumulation time of about 1 s; at the same time the value of jamming suppression ratio decreases more than by 20%. It is established that at an average speed of IS angular movement in the area of side lobes of SAR pattern equals to 0.1°/s and admissible decrease of suppression ratio of not more than 5% the rational values of sample accumulation time and of period of counting sequence make 0.1 s and 10−4 s respectively.

Barinov S.P., Maevskii Y.I., Sergeev V.I. Choice of rational timing parameters of a subsystem of spatial interference compensation in radars with synthesized aperture. Radioengineering. 2022. V. 86. № 11. P. 7−13. DOI: https://doi.org/10.18127/j00338486-202211-02 (in Russian)

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