差分合成孔径激光雷达高分辨率成像实验

High resolution imaging experiment on differential synthetic aperture ladar

利用1 550 nm波长的可调谐光纤激光器,建立了DSAL(Differential synthetic aperture ladar)高分辨率成像演示实验装置。在1.85 m的目标距离上,开展了合作目标的DSAL成像实验。利用基本的DSAL成像理论,重构了目标回波的相位史数据,实现了高分辨率合成孔径成像。详细给出了不同方位运动条件下获得的DSAL图像。实验结果表明:利用经过DSAL技术重建后的目标回波相位史数据,能够形成聚焦良好的高分辨率DSAL图像。这显示了DSAL技术对共模相位误差的稳健消除能力。此外,不同方位运动条件下的DSAL成像结果表明,在超过规定方位运动速度30%的范围内,均可观察到良好聚焦或至少可接受的DSAL图像,表明DSAL系统对方位运动速度变化有一定范围的适应能力。

Using a tunable fiber laser of 1550nm wavelength,a high resolution imaging differential synthetic aperture ladar(DSAL)was set up in the laboratory.DSAL imaging experiments were carried out using a cooperative target at distance of1.85m.The phase history data(PHD)of the target returns were reconstructed and high resolution synthetic aperture images were generated by straightforwardly following standard DSAL image formation theory.High resolution DSAL images at various azimuth moving conditions were given in detail.Experimental data show that using the reconstructed PHD by DSAL technique,much better focused images can be produced,which demonstrates that the DSAL technique can robustly remove the common phase errors in the PHD.Moreover,DSAL images with various azimuth moving conditions show that even if the azimuth speed is30%longer or shorter than its ideal value,the DSAL images are all well or at least acceptably focused,which means that a DSAL system is possibly well adaptive to the variation of its azimuth speed.