合成孔径激光雷达是利用同-孔径(望远镜)与目标作相对运动并采用信号处理方法来模拟孔径阵列,获得高方位(横向)分辨率的相干成像雷达.采用窄线宽的单频光纤激光光源和相干探测方法;发射光波被啁啾信号作幅度调制。接收后进行距离向脉冲压缩;激光雷达和目标相对运动引起的回波相位变化,由相关运算实现相位补偿和累加(孔径合成),以提高方位向分辨率.提出了新的工作体制:距离向啁啾信号调制在发射光波振幅(强度)上,方位向多普勒频移反映在回波光波相位(频率)上,便于解决距离向与方位向之间的耦合模糊问题.报道了中期实验成果:Chirp射频信号调制激光强度,实现合成孔径激光雷达距离向的压缩.
Synthetic aperture ladar(SAL) is a coherent imaging ladar which uses the the relative motion of aperture to the target and simulates apertures array with signal processing to obtain high transverse resolution. In this study, single frequency fiber laser source with narrow line width and coherent detection were employed. Transmitted optical wave was modulated with chirped signal on amplitude, and the received signal was compressed on length. The relative motion between ladar and target changes the phase of echo. Phase compensation and integration were realized by correlation operation to increase azimuth resolution. A new work style was put forward. It is convenient for solving coupling hazy problem between the range and azimuth dimension. The experiment results show that the laser intensity is modulated by chirp RF, and the range dimension compress of synthetic aperture ladar is realized.