Abstract: Considering the two issues of range migration and Doppler spectrum extension in the detection of high maneuvering targets in space-air based bistatic radar (SABBR), and on the basis of the establishment of the echo signal model and the analyses of the signal migration feature, a novel target detection algorithm suitable for SABBEWR is proposed. The Keystone transform is used to compensate the range migration in range frequency slow time domain, and the discrete chirp-Fourier transform (DCFT) is modified to estimate the target's acceleration and frequency divisor. A quadratic phase compensation function is constructed to make up for the Doppler migration. The coherent integration is performed for target detection. Simulation results show that the radial acceleration is estimated precisely, the energy of the high maneuvering target is accumulated effectivelly, and the performance detection is improved in low signal to noise ratio background.

Key words: space-air based bistatic radar, Keystone transform, modified discrete chirp-Fourier transform, quadratic phase compensation, coherent integration, target detection

摘要： 针对天空双基地雷达高速机动目标的距离徙动和多普勒频谱扩展问题,在建立目标回波信号模型及分析目标距离和多普勒徙动特性的基础上,提出了一种适用于该体制雷达的高速机动目标检测方法。首先对脉压回波信号采用Keystone变换校正距离徙动;其次对离散线性调频傅里叶变换(discrete chirp-Fourier transform,DCFT)进行修正,完成对目标加速度大小和频率因子的估计;然后根据构造的二次相位补偿函数,实现多普勒徙动补偿;最后对补偿后回波信号进行相参积累检测。仿真结果表明,所提方法对目标径向加速度的估计更准确,能有效对高速机动目标回波能量进行相参积累,提高了在低信噪比条件下的检测性能。

关键词: 天空双基地雷达, Keystone变换, 修正离散线性调频傅里叶变换, 二次相位补偿, 相参积累, 目标检测