Detection of unmanned aerial vehicle (UAV) is a challenging problem for passive bistatic radar (PBR) because of its low radar cross-section (RCS). Range migration (RM) will occur within one long coherent processing interval, which makes it difficult to increase coherent integration gain and improve radar detection ability. In order to eliminate the RM, a novel coherent integration method based on stretch processing and chirp-z transform (CZT) in the frequency domain is proposed. Firstly, stretch processing is applied to correct RM. Then, CZT is performed to mitigate the residual range offset and achieve coherent integration of the target's energy according to each Doppler cell. The advantage of the proposed method is that it can obtain superior coherent integration and detection performance compared to existing methods. Numerical and experimental results are presented to demonstrate the effectiveness of the proposed method.

对于无源双基地雷达（PBR）而言，无人飞行器（UAV）的检测是一个具有挑战性的问题，因为其雷达截面（RCS）低。距离迁移（RM）将在一个较长的相干处理间隔内发生，这使得很难增加相干积分增益和提高雷达检测能力。为了消除RM，提出了一种新的基于频域的拉伸处理和线性调频变换的相干积分方法。首先，应用拉伸处理来校正RM。然后，执行CZT以减轻残余距离偏移并根据每个多普勒单元实现目标能量的相干积分。所提出的方法的优点是，与现有方法相比，它可以获得出色的相干积分和检测性能。