Abstract:

The Linear range cell migration correction in time domain will bring about space variability in the azimuth. In this paper, a squint Synthetic aperture radar (SAR) imaging algorithm is proposed to solve the problem brought by the linear range cell migration correction in time domain, where the linear range cell migration component is corrected in azimuth Doppler domain. In this new imaging algorithm, the slant-range formula is expanded to cubic, and then the two-dimensional spectrum expression is derived by using series reversion. After that, the squint SAR imaging algorithm is proposed based on two-dimensional spectrum matched filter. This algorithm takes into account the problem of space variability in the range. At the first, the linear range cell migration correction and the pre-filter is made in the two-dimensional frequency domain, and then the algorithm of linear chirp-scaling is operated in time domain in range and frequency domain in azimuth. Finally, a well focused SAR image can be obtained after pulse pressure in two-dimensional frequency. Compared to the Range Migration Algorithm (RMA), the proposed algorithm can effectively reduce the amount of data be processed in the imaging processing. By processing the near space SAR simulation data, the effectiveness of this algorithm is proved.

Key words: Synthetic aperture radar (SAR), Linear chirp scaling, Squint imaging