合成孔径激光雷达下视三维成像构型及算法

传统激光三维成像均采用实孔径成像技术,其分辨率会随着作用距离的变远而降低。相比于实孔径成像,合成孔径成像的一个显著优势是沿航向的分辨率不随作用距离的变化而变化。基于合成孔径技术提出一种合成孔径激光三维成像雷达的工作模型。该系统采用激光泛光发射模式和多波束相干接收,首先,在高度向,采用大时宽带宽的线性调频信号,并利用解线频调技术实现高分辨率;其次,沿航向利用合成孔径技术频域压缩算法实现高分辨率,其中考虑到激光调频信号的长扫频周期,对于平台连续运动引入的多普勒平移项进行了补偿;在跨航向通过实孔径阵列实现高分辨率。最后,通过仿真实验验证了该系统的有效性。

Downward-looking 3-D imaging configuration and algorithm for synthetic aperture ladar

Traditional 3-D laser imaging systems are based on real aperture imaging technology, whose resolution would decrease with range's increasing. An advantage of synthetic aperture imaging technology over real aperture imaging is that the resolution of the imaging system is constant with range's increasing. In this paper, a novel 3-D imaging system was given, which was based on synthetic aperture technology. According to the characteristic of the signal, a suitable data progressing method was proposed based on the flood-light transmitting mode and multi-beam receiving mode. Firstly, in the range dimension, the signal with large time bandwidth product was adopted to obtain high resolution with the help of dechirp technology. Secondly, in the along-track dimension high resolution was obtained by synthetic aperture technology, in which the phase error caused by long scan duration was taken into account and compensated. Thirdly, in the cross-track dimension traditional real aperture array imaging method was adopted. Finally, simulation was provided to demonstrate the effectiveness of the proposed system.