Affiliation:
1. Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China
2. University of Chinese Academy of Sciences, Beijing 100049, China
Abstract
The wide-field imaging system carried on a high-altitude or near-space vehicle takes high-resolution images of the ground to measure and map targets. With the improvement of imaging resolution and measurement accuracy, the focal length of the wide-field imaging system is getting longer. The requirement for image motion compensation (IMC) accuracy is getting higher, and the influence of optical path coupling is increasing within the process of two-dimensional (2D) IMC. To further improve the IMC accuracy of the wide-field imaging system, an innovative IMC method is first proposed in this paper. The method is based on the 2D motion of the scanning platform and secondary mirror. Secondly, to solve the optical coupling problem in the process of 2D IMC, the coupling phenomenon is analyzed. The coupling relationships between 2D scanning motion, 2D secondary mirror motion and image motion is derived from the compensation process. A complete 2D IMC model is established, and a 2D IMC method, including an optical path decoupling correct regulator (ODCR), is designed. Finally, the method is verified in laboratory and field flight tests. The results show that the proposed method can effectively correct the coupling error of the optical path in the process of IMC and achieve high-resolution 2D IMC. When the scanning speed is 60°/s and the exposure time is 2 ms, the accuracy of the 2D IMC is up to 0.57pixels (RMS) in the pitch direction, and 0.46 pixels (RMS) in the roll direction.
Subject
Radiology, Nuclear Medicine and imaging,Instrumentation,Atomic and Molecular Physics, and Optics
Reference38 articles.
1. Robust video stabilization based on particle filter tracking of projected camera motion;Yang;IEEE Trans. Circuits Syst. Video Technol.,2009
2. Design considerations for optical pointing and scanning mechanisms;Sweeney;Proc. SPIE Optomech.,2003
3. Gorin, B.A. (2003, January 8). Side oblique real-time orthophotography with the 9Kx9K digital framing camera. Proceedings of the Society of Photo-Optical Instrumentation Engineers Conference on Airborne Reconnaissance, Orlando, FL, USA.
4. Benzarti, F., and Amiri, H. (2013). Repairing and Inpainting Damaged Images using Diffusion Tensor. arXiv.
5. Pratlong, J.A., Jerrama, P., and Tsiolisa, G. (2018). TDI-CMOS Image Sensor for Earth Observation. Sens. Syst. Next-Gener. Satell.