光学学报, 2014, 34 (5): 0528001, 网络出版: 2014-04-25
自干涉合成孔径激光三维成像雷达原理
Principle of Self-Interferometric Synthetic Aperture Ladar for 3D Imaging
成像系统 合成孔径激光成像雷达 直视合成孔径激光成像雷达 干涉合成孔径雷达 三维地形浮雕成像 扫描柱面镜位置偏置 imaging systems synthetic aperture imaging ladar (SAL) down-looking SAL interferometric synthetic aperture radar 3D topography relief imaging position biasing of scanning cylindrical lens
摘要
在直视合成孔径激光成像雷达(SAL)的基础上,提出了一种自干涉的产生三维成像的原理方法。首先对于交轨向正扫描和反扫描的柱面镜进行位置偏置,造成交轨向成像频谱的平移并产生相对线性相延,然后逐一对一对交轨向正扫描和反扫描收集聚焦像进行相干叠加,并由此产生自干涉。自干涉产生的交轨向平展条纹对于目标面的倾斜投射即可产生包含目标高度信息的波痕干涉图,最后通过解包裹算法产生表征目标表面轮廓的等位线图。本方法采用一发一收的雷达结构通过单航过干涉法实现三维成像,结构简单,原理有效,同时具有抗大气、运动平台等相位干扰能力。
Abstract
On the basis of down-looking synthetic aperture ladar (DL-SAL), a kind of self-interferometric SAL for 3D topographic relief imaging is proposed in this paper. Firstly, the forward-scanning and backward-scanning cylinder lenses for imaging along the orthogonal direction of travel are biased in their positions, it thus introduces a shifted spectrum image with a linear phase term. Then pair of a forward-scanning resulted focused image and the next backward-scanning resulted image are coherently added, therefore a self-interference between the two images occurs. The flat fringes from this self-interference can be obliquely projected to a target plane, so that a subtly rippled interferogram containing the target height information can be observed. Finally, by using the unwrapping algorithm, a contour mapping representing the surface profile will be achieved. This SAL including a transmitter and a receiver realites the 3D imaging by a one-pass interferometry. The features are simple in construction and effective in principle. Moreover, the phase errors from the atmospheric turbulence can be automatically compensated.
刘立人. 自干涉合成孔径激光三维成像雷达原理[J]. 光学学报, 2014, 34(5): 0528001. Liu Liren. Principle of Self-Interferometric Synthetic Aperture Ladar for 3D Imaging[J]. Acta Optica Sinica, 2014, 34(5): 0528001.