光学 精密工程, 2017, 25 (7): 1738, 网络出版: 2017-10-30
光度数据反演临近空间低速点目标形状尺寸信息
Inversion of low dynamic vehicle shape and dimension information using non-resolved photometric data in near space
摘要
为了获取临近空间低速点目标的形状尺寸信息, 进行了高空气球光学观测实验, 研究了如何从光度数据中反演低速点目标形状尺寸信息。利用孔径测光技术处理地基探测装备所拍摄的实验图像数据获取目标光度数据。在反演过程中, 采用球谐函数法和细分控制点法两种形状描述方法来参数化描述目标形状, 利用球谐函数法的正则化函数、三角面元正则化函数和基于目标物理特性的正则化函数约束目标的形状变化, 在对目标光度数据以及由两种形状描述方法产生的模型数据进行傅里叶变换的基础上, 结合光学系统点扩散函数来反演空间目标形状尺寸信息。结果表明: 两种形状描述方法反演的目标形状主要特征相似, 表明这种形状特征是从光度数据提取到的。球谐函数法和细分控制点法反演出的目标等效直径相对误差分别为11.3%和22.6%, 长度相对误差分别为11.6%和21.8%。由此表明: 球谐函数法反演的临近空间低速目标形状误差较小, 更能准确地反演出临近空间低速目标形状。
Abstract
In order to obtain the shape and dimension information of low dynamic non-resolved object in near space,an experiment on optical detection of high altitude balloon was performed to investigate how to calculate object shape and dimension information from photometric data. In the experiment, experimental images captured by the ground-based detector were processed by aperture photometry technology, thus obtaining non-resolved photometric data. During the inversion process, two shape representation methods as well as three sets of regularization functions were adopted to describe and restrict object shape, respectively. The methods contained spherical harmonics function and subdivision control points, and the functions involved spherical harmonics regularization function, triangle panel regularization function and physical characteristics regularization function. Based on the Fourier transform of photometric data and model data of the shape representation methods, the shape and dimension information of the non-resolved object was inversed by the Point Spread Function (PSF) of the optical system. The result shows that the prominent features presented in the object shape are similar, which indicates that the features are extracted from the photometric data. The relative errors of object equivalent diameter inversed by spherical harmonics function and subdivision control points are 11.3% and 22.6%, and the relative errors of object length are 11.6% and 21.8%, respectively. The comparison of the relative errors proves that the shape representation method based on the spherical harmonics function has smaller error and is more suitable to represent the low dynamic object shape.
荆楠, 李创, 钟培峰, 崇雅琴. 光度数据反演临近空间低速点目标形状尺寸信息[J]. 光学 精密工程, 2017, 25(7): 1738. JING Nan, LI Chuang, ZHONG Pei-feng, CHONG Ya-qin. Inversion of low dynamic vehicle shape and dimension information using non-resolved photometric data in near space[J]. Optics and Precision Engineering, 2017, 25(7): 1738.