Temperature variations will affect the geometric and optical characteristics of the camera and lens in the videometric system, especially when the optical systems are working in a long period. The paper presents an analysis of the image drift caused by temperature variations and the corresponding temperature compensation method. Firstly, image drift model is established based on the pinhole camera model; then two simplified models are introduced by analyzing the coupling relations between the variations of camera parameters and temperature; furthermore, influence of temperature changes on camera parameters were modeled and calibrated; pose estimation experiments as well as temperature compensations are also conducted in deformation measurements, and the results prove the feasibility and efficiency of the proposed models.
Proc. SPIE. 9142, Selected Papers from Conferences of the Photoelectronic Technology Committee of the Chinese Society of Astronautics: Optical Imaging, Remote Sensing, and Laser-Matter Interaction 2013
KEYWORDS: Aerospace engineering, Imaging systems, Cameras, Reliability, Surveillance, Finite element methods, Defense technologies, Thermal modeling, Temperature metrology, Chaos
When the videometric method is working during a long period, the temperature effects on cameras and lens will cause changes in optical axis, focal length and aberration coefficients, so as to influence the accuracy and reliability of measurement results. The features of typical structure of camera lens when it is applied by thermal stress are analyzed in this paper. The model of key parts of camera lens which influence the measure accuracy mostly is built firstly, then the thermal stress is calculated and the influence of thermal transmutation to the measure accuracy is analyzed. Finally, suggestion to improve the structure of camera lens is proposed.