Based On The Technology Of Antenna Phase Center Offset Airborne Synthetic Aperture Radar Imaging Studies

Synthetic aperture radar (SAR) is a very mature and most widely used technologyin the field of microwave imaging. Because it enables versatile and detailed imagery ofthe Earth’s surface almost independently of light and weather conditions, such as clouds,fog, and rain, It has been widely used in environmental protection, disaster monitoring,marine observation, resource exploration, precision agriculture, geological mapping andso on. In recent years, more powerful synthetic aperture radar has been expected, higherresolution and wider swath has become the development trend of the of the syntheticaperture radar, conventional SAR systems with a single transmit and receive antenna arenot capable of fulfilling the increasing demands for improved spatial resolution andwider swath coverage. Therefore, it is necessary to explore new mechanism of syntheticaperture radar to meet the high-resolution wide-swath imaging demands.At first, this paper offers a brief description of the development history, thetechnology characteristics, as well as the basic principle of the synthetic aperture radar.Based on the establishment of the echo model of the traditional single-antenna syntheticaperture radar, a detailed study of the Chirp Scaling imaging algorithm is processed.Then in order to overcome the limitations of the single-aperture system, displaced phasecenter antenna (DPCA) technology is applied. This technology uses a biostatic antennaand displaces several receiving apertures in azimuth, and the phase centers of them havean offset to the transmission aperture, all of the receiving apertures receive echoesindependently. By appropriate adjustment of the phase center spacing, we can getadditional degrees of freedom, making it possible to achieve high-resolution wide-swathimaging. However, this technique imposes a stringent requirement on the systemparameters, which will lead to non-uniform sampling in azimuth, and it thus cannotdirectly use the conventional imaging algorithms to process the echo data. To solve thisproblem, multi-channel reconstruction algorithm is used to preprocess the echo data tocorrect the non-uniform sampling. Then several simulations are performed to verify thedescribed algorithm.