Chirp强度调制与近红外激光合成孔径雷达距离向处理

合成孔径激光雷达是利用同一孔径(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.

Chirped AM and near infrared synthetic aperture ladar range dimension processing

Synthetic aperture ladar is a coherent imaging ladar which uses relative motion of aperture to the target and signal processing to simulate apertures array to obtain high transverse resolution. Narrow line width single frequency fiber laser sour and coherent detection is employed; transmitted optical wave is modulated with chirped signal on amplitude, the received signal is compressed on length. Relative motion between ladar and target changes the phase of echo . Phase compensation and integration by correlation operation increases azimuth resolution. We bring forward a new work style: chirped signal on range dimension was modulated on optical signal amplitude, Doppler frequency shift on azimuth dimension changes optical wave phase (frequency) of echo , which is convenient for resolving coupling hazy problem between range and azimuth dimension. We report part experiment result : laser intensity was modulated with chirp RF, then range dimension compress for synthetic aperture ladar was realized.