基于编码项补偿的OFDM信号SAR成像

The Imaging of SAR Based on OFDM Waveforms Signal with the Compensation of Coding Term

该文探讨了正交频分复用(OFDM)波形在SAR中可能的应用,重点讨论了基于该信号体制的SAR成像。OFDM波形改变了传统线性调频信号平坦的频谱,给高分辨成像带来了新的问题。该文深入分析了OFDM波形的信号特点,推导了其2维频谱,提出了一种适合OFDM SAR精确成像的方法。该成像算法利用对编码项的补偿,实现了OFDM波形下的距离迁徙校正,有效降低了编码信号对旁瓣的影响,充分提高了OFDM波形的成像性能。仿真结果验证了所提方法的有效性。

The potential application of OFDM waveforms in SAR is considered in this paper, especially for the SAR imaging based on OFDM waveforms. The OFDM waveforms destroy the flat spectrum from the conventional Linear Frequency Modulation （LFM） waveform, which bring difficulties to high resolution imaging. This paper first analyzes the characteristics of OFDM waveforms in detail, derives its two-dimensional spectral, then proposes a novel algorithm for the high resolution imaging based on OFDM waveforms. This algorithm is based on the compensation of coding term. It manages Range Cell Migration Correction （RCMC）, suppresses the sidelobe from coding, and improves the imaging performance greatly. The simulation results prove the validity of this algorithm.