I. Introduction
With the development of science technology, especially the highly maneuvering target and high-resolution imaging technique, there is a growing need for detection of maneuvering targets with complex motions in radar society [1]–[5]. The detection performance of moving targets affects the imaging quality, target tracking and recognition significantly [6]–[10]. It is known that the coherent integration technique, which is widely used for coherent search radar, can increase the signal-to-noise ratio (SNR) and thus improve the radar detection ability [11]–[13]. Unfortunately, the complex motions of maneuvering targets, e.g., high velocity, acceleration and jerk, involves the range migration (RM) and Doppler frequency migration (DFM) within one coherent pulse interval, which result in serious performance loss for the coherent integration processing [14]–[16].