基于子带补偿的弹载聚束SAR成像算法

An imaging algorithm for missile-borne spotlight SAR based on subband compensation

弹载SAR成像常用非线性变标类算法改善聚焦效果.然而,非线性变标算法由于自身的局限性,在三维匀加速聚束SAR成像模式中非常容易失效.针对这一问题,本文提出了一种子带补偿法,并将该方法结合到弹载SAR聚束成像算法中.新算法不引入三次相位操作,可有效补偿随目标位置走动的多普勒调频率.仿真结果和分析表明,与常用的非线性变标类算法相比,本文所提算法在运算量、成像结果、适用性上都具有优越性,具有一定的工程应用价值和理论意义.

The missile-borne synthetic aperture radar（SAR） often use nonlinear scaling algorithm to improve the focusing effect. However, the nonlinear scaling algorithm cannot be used in missile-borne spotlight SAR because of its own limitations. Aiming at this problem, this paper first puts forward a new method named ＂sub-band compensation＂ and combineds it to the missile-borne SAR spotlight imaging algorithm. This new algorithm does not introduce the three phases of operation, so the Doppler frequency rate can be effectively compensated under low PRF. Simulation results and analysis show that compared with the nonlinear chirp scaling algorithm, the proposed one has advantages in computation,results obtained, and applicability.