Complete Complementary Sequence Coding Waveform Based Azimuth Multi-Channel Space-Borne Sar With Ultra-Low Range Sidelobe Ratio Performance

Abstract

Abstract-Sidelobes of strong targets substantially impact image quality of synthetic aperture radar (SAR) using linear frequency modulation (LFM) waveform, especially in urban areas. A novel space-borne azimuth multi-channel SAR scheme with ultra-low range sidelobe-ratio (RSLR) performance was proposed, employing complete complementary sequence (CC-S) coding waveform.The CC-S waveform was utilized to acquire ultra-low RSLR performance in range direction. Azimuth multi-channel scheme was introduced, to compensate reduction of effective PRF due to employing CC-S, and to mitigate azimuth resolution lost resulted from strong azimuth weighting, in order to implement low side-lobe performance in both range and azimuth direction. The method for pre-processing the CC-S based multi-channel SAR data was proposed, which would both compensate receiving time difference of sub-sequences and reconstruct azimuth spectrum of multi-channel SAR data. Furthermore, the corresponding image formation algorithm for accurately focusing raw data of the SAR system was also proposed. Computer simulation results were presented, which demonstrated the validity of the proposed SAR scheme and image formation algorithm.

Perfect orthogonal waveform scheme used for high-resolution multiple-input multiple-output synthetic aperture radar system

“…[25][26][27] Recently, some literatures refer to MIMO radar based on CCS. 28,29 A systematic approach of constructing Doppler resilient complete complementary code is introduced and the ambiguity function is analyzed. 28 One group of CCS coding waveform-based azimuth multichannel SAR system with ultra-low-range side-lobe ratio performance is designed.…”

“…28 One group of CCS coding waveform-based azimuth multichannel SAR system with ultra-low-range side-lobe ratio performance is designed. 29 This paper will extend the CCS as transmitting signal in MIMO SAR system to heighten the image formation quality. By utilizing the multiple subsequences of CCS, the transmitted signals from different antennas are modulated into distinct center frequencies in the azimuth direction.…”

“… – 24 CCS is often used as spread spectrum signal to combat the multipath interference or utilized as training sequence to improve the accuracy of channel estimation in MIMO communication system 25 – 27 Recently, some literatures refer to MIMO radar based on CCS 28 , 29 . A systematic approach of constructing Doppler resilient complete complementary code is introduced and the ambiguity function is analyzed 28 .…”

“…A systematic approach of constructing Doppler resilient complete complementary code is introduced and the ambiguity function is analyzed 28 . One group of CCS coding waveform-based azimuth multichannel SAR system with ultra-low-range side-lobe ratio performance is designed 29 . This paper will extend the CCS as transmitting signal in MIMO SAR system to heighten the image formation quality.…”