空间目标往往具有很高的速度,甚至还具有一定的加速度,回波信号经过去斜率处理后仍然是一个多分量的多项式相位信号,高阶相位使得目标的一维距离像产生畸变,脉冲压缩前必须进行运动补偿,否则无法得到正确的一维距离像。本文以平均距离像最小熵准则为基础,提出了一种基于测距元参数化模型的空间目标一维距离像畸变补偿技术。根据空间目标的运动特性,建立了目标测距元的参数化模型。结合雷达的宽窄带测元信息,以平均一维距离像的熵作为目标函数,建立了测距元模型参数估计的优化模型和算法,并利用该参数对一维距离像进行运动补偿。仿真结果验证了本文算法的有效性。
Space targets usually orbit with high speed a certain level of acceleration,which makes the dechirped return signal be a multi-component signal with polynomial phase.Since the high order phases will distort the high resolution range profiles,the process of motion compensation is necessary before pulse compression.Otherwise,one can not get the correct high resolution range profiles.In this paper,a parametric model based on range measurements is proposed to compensate the distortion of range profiles.According to the motion characteristics of space target,a parametric model of the ranging element is established.Wih the application of the ranging information obtained by the wideband and narrowband signals,an objective function based on the entropy of the average range profile is minimized to estimate the parameters in the established model,with which the distortion of range profile is well compensated.Simulations verify the effectiveness of the proposed algorithm.