A Novel Channel Calibration Method for Bistatic ISAR Imaging System

Applied Sciences

Lin Shi¹  Chaoxuan Shang¹  Huiyan Zeng¹  Baofeng Guo¹  Juntao Ma¹ 

[1] Department of Electronic and Optical Engineering, Army Engineering University Shijiazhuang Campus, Shijiazhuang 050003, China;

关键词: bistatic inverse synthetic aperture radar;    channel calibration;    external calibration;    coherent accumulation;   

DOI  :  10.3390/app8112160

来源: DOAJ

【 摘 要 】

In practical bistatic inverse synthetic aperture radar (ISAR) imaging systems, the echo signals are modulated by non-ideal amplitude and phase characteristics of the transmitting and receiving channels, which seriously distorts image quality. However, the conventional channel calibration method based on a transponder is not applicable to bistatic ISAR imaging systems, since the baseline of the system is up to hundreds of kilometers. A channel calibration method only using calibration satellite echo information is proposed for the system, with a linear frequency modulation (LFM) waveform. Firstly, echoes of the calibration satellite are collected by tracking the satellite and multi-period echoes are aligned in the time domain, according to the pulse compression result. Then, the signal to noise ratio (SNR) is improved by accumulating multi-period echoes coherently in the time domain and the calibration coefficient is constructed based on the accumulated signal. Finally, spectrum of the echo signal is multiplied with the calibration coefficient to compensate the influence of channel characteristics. The effectiveness of the proposed method is verified by the simulation experiment with real satellite echoes.

【 授权许可】

Unknown