MULTIPLE-SWATH STRIPMAP SAR IMAGING METHOD

摘要

The present invention concerns a SAR imaging method, which comprises performing N SAR acquisitions in stripmap mode of areas of the earth's surface by means of a synthetic aperture radar that is transported by an aerial or satellite platform and which comprises a single, non-partitioned antenna and a single receiver coupled to said single, non-partitioned antenna, N being an integer greater than one. Each SAR acquisition in stripmap mode is performed using a respective squint angle with respect to the flight direction of the synthetic aperture radar, said respective squint angle being equal to, or different from, the squint angles used for performing the other N-1 SAR acquisitions in stripmap mode. Each SAR acquisition in stripmap mode is performed using a respective elevation angle with respect to the nadir of the synthetic aperture radar, said respective elevation angle being different from the elevation angles used for performing the other N-1 SAR acquisitions in stripmap mode, thereby resulting in that each SAR acquisition in stripmap mode is related to a respective swath of the earth's surface which is different from the swaths observed via the other N-1 SAR acquisitions in stripmap mode. Each performed SAR acquisition in stripmap mode comprises respective radar transmission and reception operations that are time interleaved, individually or in groups, with single, or groups of, radar transmission and reception operations of the other N-1 SAR acquisitions in stripmap mode performed, and which comprise the transmission and reception of respective radar beams in respective acquisition directions that are defined by the respective squint angle and by the respective elevation angle used for said SAR acquisition in stripmap mode, thereby resulting in that said respective acquisition directions are parallel to each other and not parallel to the acquisition directions of the other N-1 SAR acquisitions in stripmap mode performed. The method further comprises generating, on the basis of each SAR acquisition in stripmap mode performed, SAR images of areas of the respective swath observed via said SAR acquisition in stripmap mode. All the SAR images generated have one and the same azimuth resolution that is equal to half the physical or equivalent length along the azimuth direction of the single, non-partitioned antenna of the synthetic aperture radar.