A Novel Channel Calibration Method for Bistatic ISAR Imaging System

Abstract

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.

Bistatic ISAR distortion mitigation of a space target via exploiting the orbital prior information

“…Hence, Bi‐ISAR becomes an effective method of the surveillance of space targets [10–14]. The research of Bi‐ISAR including the imaging principle, algorithm, and application has attracted much attention recently [9, 15–22].…”

Bi‐ISAR sparse imaging algorithm with complex Gaussian scale mixture prior

“…better detection performance of stealthy targets, strong anti‐interference and information acquisition ability [7–11]. The research of Bi‐ISAR with respect to the imaging principle, algorithms and applications has attracted much attention recently [12–18].…”

High-Resolution Bistatic ISAR Imaging of a Space Target with Sparse Aperture

“…A high-resolution image of Bi-ISAR provides more target details, which is beneficial to further target classification and recognition [3][4][5][6][7][8]. Hence, high-resolution Bi-ISAR systems have been an important technique of space target surveillance [9][10][11][12][13][14].…”