Long‐time coherent integration based on intra‐partition range‐Doppler processing for passive bistatic radar

Abstract

The Doppler mismatch, range migration and Doppler frequency migration (DFM) correction problem for realizing the long-time coherent integration of space moving target with high-speed manoeuvring performance in passive bistatic radar is considered. A novel method based on intra-partition range-Doppler (RD) processing is proposed, where the intra-partition RD processing is first performedtoachievethe pre-accumulationof target's energy in each partition and eliminate the Doppler mismatch. Then, the generalized keystone transform is employed to correct the range curvature. After that, the residual range walk is removed with the centre frequency of the coarse Doppler filter related to the target velocity. Furthermore, matched filtering process is carried out to compensate the DFM. The advantage of the method is that it can obtain superior coherent integration and detection performance in comparison with the existing algorithms. Numerical simulations are presented to demonstrate the coherent integration and the detection performance for a highspeed target. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.

A Quasi-Coherent Detection Method Based on Radon–Fourier Transform Using Multi-Frequency-Based Passive Bistatic Radar

“…RCM causes the energy of the target echo to disperse in multiple range units, which reduces the processing gain of long-time integration. According to [20], RCM occurs when the following equation is satisfied,…”

“…To cope with this limitation and achieve a robust detection of moving targets, long time integration and increasing the number of fusion channels are required to enhance the SNR of the weak echo. However, both of these will result in the energy misalignment [19], which can be divided into two parts: range cell migration (RCM) and Doppler frequency migration (DFM) [20]. Specifically, the target's energy will disperse in multiple range cells due to the effect of RCM.…”

“…To circumvent this effect, a number of channels with consistent bandwidth are selected so that the target will locate in the same range bin at different frequency bands, due to the same physical path and range resolution. On the other hand, the conventional DFM is generated by the maneuverability (i.e., acceleration or jerk) of a moving target [20]. Typical methods for solving the DFM effect could be the phase matching (PM) approach [24], de-chirp method [25], chirp-Fourier transform [26], and fractional Fourier transform (FRFT) [27], etc.…”