Title :
Improved RMA based on Nonuniform Fast Fourier Transforms(NUFFT’s)
Author :
Wu, Yong ; Song, Hongjun ; Shang, Xiuqin ; Zheng, Jingbo
Author_Institution :
Inst. of Electron., Chinese Acad. of Sci., Beijing
Abstract :
Range Migration Algorithm (RMA) can perfectly fulfill the focusing of the whole scene under the condition of wide aperture and large squint angles. However, Stolt interpolation is needed in regular RMA and is time-consuming. In this paper, an improved RMA algorithm based on Nonuniform FFT (NUFFT) is developed for SAR imaging. NUFFT is substituted for the Stolt interpolation and range IFFT in the improved RMA. In this work, the principle of NUFFT and its implemented steps are analyzed in detail first. Then SAR echo signal model is introduced including the geometric model and the expression of echo signal in both time and frequency domain. Besides, algorithm flow of Regular RMA and the improved RMA based on NUFFT are given. Simulation based on SAR echo model is performed and imaging effects are compared in different squint angles. Numerical simulations illustrate the performance of the improved method. The improved RMA based on NUFFT can satisfy both the imaging precision and computation efficiency.
Keywords :
echo; fast Fourier transforms; interpolation; radar imaging; synthetic aperture radar; SAR imaging; Stolt interpolation; echo signal model; geometric model; imaging effects; nonuniform fast Fourier transforms; range migration algorithm; Apertures; Approximation error; Computational modeling; Focusing; Frequency domain analysis; Interpolation; Layout; Numerical simulation; Radar polarimetry; Solid modeling; Nonuniform Fast Fourier Transform(NUFFT); Range migration algorithm(RMA); Synthetic Aperture Radar(SAR);
Conference_Titel :
Signal Processing, 2008. ICSP 2008. 9th International Conference on
Conference_Location :
Beijing
Print_ISBN :
978-1-4244-2178-7
Electronic_ISBN :
978-1-4244-2179-4
DOI :
10.1109/ICOSP.2008.4697654
