基于包络相关法的包络对齐方法改进

在ISAR成像数据录取跟踪过程中，目标姿态突变等因素将造成回波中存在一些对成像作用较小且降低成像质量的数据，致使传统包络相关法的对齐精度不高。文中提出了一种改进措施，先用包络相关法进行初步对齐，接着将降低成像质量的数据剔除，再利用包络相关法进行包络对齐。该方法通过分析回波数据的一维距离像与成像数据的平均一维距离像的归一化相关系数，判断数据是否为降低成像质量的数据，进而对其进行剔除。实测数据成像对比实验表明，该方法是有效的。

The Amelioration of Envelope Alignment Based on Envelope Correlation Method

In the data collection and tracking for ISAR,a kind of data that has poor function of decreasing the image quality is gathered due to the change of target's stance.The existence of the data reduces the precision of classic envelope correlation method.In order to resolve the problem mentioned above,an improved method is given.In the method,firstly,the data that decreases the image quality are eliminated after dealing with envelope correlation method;and then,the classic envelope correlation method is used again for range alignment.In the method,the data that decreases the image quality are judged and eliminated by the analysis of the normalized correlation coefficient between the range profile of each echo and the mean range profile of all the data for imaging.The method is tested by factual data,and the result indicates the validation of the method.