An Accurate Resampling Strategy for Spaceborne SAR With PRI Variation

Inhalt:
For spaceborne high-squint spotlight synthetic aperture radar, the range migration can be comparable to the swath width. In this case, the effective data rate can be significantly increased by continuously varying the pulse repetition interval (PRI) according to the change of the slant range. This paper presents an accurate resampling strategy for the nonuniform data caused by the PRI variation. A novel preprocessing is proposed to resolve the spectrum aliasing, which improves the accuracy of the subsequent resampling realized by the weighted nonuniform fast Fourier transform. Simulation results have verified the effectiveness of the proposed strategy.