A motion compensation approach integrated in the omega-K algorithm for airborne SAR

Abstract

The omega-K algorithm has been considered unable to be combined with high-precision motion compensation (MoCo). An extended omega-K (EOK) algorithm was proposed in which the two-step MoCo could be integrated. However, the second-order MoCo is inaccurate due to the wavelength-dependent scaling of the azimuth signal after the modified Stolt mapping. Although a third-step MoCo was introduced to make up for this drawback, it is limited in dealing with high-frequency motion errors because it is applied block-wise in the time domain. A MoCo approach is proposed in this paper integrated in the traditional omega-K algorithm, which implements the aperture-dependent second-order MoCo after the range compression and before the Stolt mapping. Theoretical analysis and simulation verifies its validity.