步进频率线性调频脉冲信号的子孔径处理方法

针对步进频率线性调频脉冲信号的压缩处理提出频域子孔径处理方法。该方法首先将每个子脉冲的回波信号在频域进行匹配滤波,经频谱搬移和相干合成后,得到距离时间函数的频域响应,最后进行逆FFT从而得到一维距离像,实现脉冲压缩。介绍了频域-时域混合的子孔径处理法,即首先将子脉冲在频域进行匹配滤波并变换到时域,经过时域上变频,然后在时域进行相干合成。针对不同孔径的加权方法作了计算,并进行比较和分析。计算表明,孔径加权的效果与Chirp信号的基带带宽以及步进频率大小有关,在实际中应该针对不同情况采用不同的加权方法。所提方法对频率线性步进和非线性步进的情况都适用。

Subaperture processing method for stepped-frequency Chirp signal

A subaperture processing method is proposed for stepped frequency chirp signal(SFCS) compression.In this method,matched filtering for the echo of each transmitted subpulse is firstly performed,the filtered spectrum is then up moved,and coherently combined in frequency domain,and finally,IFFT is performed to get range profile.Another approach, by which the echo of each subpulse is firstly matched filtered,then digitally up mixed,and finally combined in time domain,is also introduced.Different methods of windowing are applied and compared with each(other.) Simulations show that different windowing methods affect the compression result dramatically.The method is suitable for both linearly stepped case and nonlinearly stepped case.