High azimuth resolution wide swath imaging based on the intrapulse spotlight SAR

With respect to the contradiction between high azimuth resolution and wide swath, the intrapulse spotlight synthetic aperture radar (SAR) mode is presented to achieve high azimuth resolution wide swath imaging. Firstly, the model of intrapulse spotlight SAR is established, and then the characteristic of echoes in this mode is analyzed in detail. A conclusion that the intrapulse scanning can make point targets in the different azimuth subswaths ambiguous is given. The degrees of freedom along the pitching direction are used to remove the range ambiguities. In the intrapulse spotlight SAR mode, the long synthetic aperture acquired by intrapulse scanning technique is used to realize high azimuth resolution. Meanwhile a low pulse repetition frequency (PRF) is adopted to achieve wide swath. Results of simulation show the effectiveness of this method.