中文摘要：

在不增大功率孔径积的同时，数字阵列雷达通过灵活的波束控制可增加目标驻留时间，并提高微弱目标的检测性能。但是，随着积累时间增长，运动目标存在跨距离单元问题。针对Keystone变换长时间目标积累方法在多普勒模糊情况下对某些特定速度的目标性能下降问题，提出了一种改进的基于Key—stone变换的长时间目标积累方法。新方法通过预处理及修正处理，能够对所有速度的目标均能较好地补偿跨距离单元效应。仿真实验验证了该方法的有效性。

英文摘要：

Rather than increasing the power-aperture product, digital array radar（DAR） can increase the dwell time on targets and significantly enhance the detection performance for weak targets by the way of flexible beam control, However, the integration and detection methods for such long dwell time should deal with the problem resulting from target range-cell-crossing. This paper presents an improved Keystone-transform based method for long-time coherent integration, which can deal with the performance degradation for specific targets with certain velocity. The new method compensates the range-cell-crossing effect for all targets with all velocity by preprocessing and correcting operation. The effectiveness of new method is conformed by the simulation results.