基于改进Keystone变换的高速目标相参积累方法

A Method of High-velocity Target Coherent Integration Based on Improved Keystone Transform

Keystone变换常常用于校正运动目标在脉冲多普勒雷达相参积累时间内的距离走动,提高回波信号的信噪比。但是常规Keystone变换应用于高速目标会存在两方面问题,首先常规Keystone变换引入插值增加了运算负担,其次若存在多普勒模糊,常规Keystone变换实现方法会出现"半盲速点"效应。文中提出了基于尺度变换的Keystone变换方法,新方法可以明显减少运算量,减小了带宽对多普勒模糊的影响,抑制了"半盲速点"效应,提高了相参积累效果。

Keystone transform can correct range migration on the moving target in the PD radar coherent integration time, and im- prove the signal-to-noise ratio of the echo signal. But conventional Keystone transform applied to the high-velocity target will have two problems. Firstly, conventional Keystone transform increases computation burden with interpolation. Secondly, with Doppler ambiguity, ＂half-blind-velocity effect＂ occurs when the conventional implementation method of Keystone transform is applied. The paper presents novel Keystone transform based on chirp scaling. It can obviously reduce computation cost and influence of band- width on Doppler ambiguity, suppress ＂half-blind-velocity＂ and improve the performance of coherent integration.