Word length optimization for sliding spotlight SAR imaging

With the development of the high-resolution synthetic aperture radar (SAR) technology, the spaceborne SAR has become a hot research topic. However there is a contradiction between hardware resource occupation and imaging accuracy in hardware implementation. Realizing the algorithm with the fixed-point instead of the floating-point is an effective solution for this problem. In this paper we propose a method in which the fixed-point is used for all FFT operations rather than entire operations of algorithm. We simulate the point target and area target. We evaluate the image quality to obtain the relationship between the word length and SAR imaging assessment indexes. The results show that the 13-bit word length can make a good balance between hardware resource occupation and sliding spotlight SAR imaging accuracy in the case of 16384×8192 imaging granularity and 1m resolution.