In the light of optical-electronic imaging system ,designed a continuous zoom lens with a optical aperture of 60mm and a zoom range of 18-246mm. Summarized the disadvantages of the former zoom lens and a low temperature resistant and high precision structure ,named the special-shaped slide and cam zoom structure is proposed, and carrying out the theoretical analysis and the detailed structural design. Theoretical analysis shows that this kind of structure can make the sliding friction between the cam and the main mirror tube turned into rolling friction ,thus reducing the torque demand.it also helps to eliminate the stuck phenomenon of the cam in low temperature environment .The special-shaped slide frame structure can help eliminate the tilt Angle of the moving mirror group in the zoom process ,thus reducing the variation of optic axis .In the he final test, the zoom time is not longer than 8s in the environment which temperature is only -45°C，and the variation of optic axis is smaller than 0.3milliradian,both meet the target requirement.
Thermal control and temperature uniformity are important factors for space remote sensing cameras. This paper describes the problems with existing systems and introduces the thermal design of a space optical remote sensing camera. Firstly, based on the theory of wave-front aberration distribution, the thermal control index of a space remote sensing camera is proposed. Then on the basis of the analysis of the heat flux environment outside the camera space, the thermal optical analysis of the camera is performed by using the finite element analysis method at high and low temperature conditions. The results show that the transfer function of the optical system with the resolution of 50 lp in the full field of view is more than 0.4. The optical design index can be satisfied, and the rationality of the thermal design is verified. The simulation result meets the requirements of optical design very well. Therefore the study in this paper can be used as an important reference for other space optical systems, which has certain engineering significance.
Compared with visible light imaging systems, the infrared imaging systems have the advantages of strong fogging ability, especially in the high-altitude water vapor and haze environment. and the medium-wave infrared cooling detectors have the advantage of low cost compared to long waves. Therefore, in recent years, The demand for medium-wave infrared continuous zoom systems is increasing. In this design, based on the medium-wave infrared optical system, and summarizing the advantages and disadvantages of the previous zoom structure, a zoom mechanism in the form of a cam and guide was proposed. The cam mechanism, zoom guide mechanism, and compensation guide mechanism were described in detail in this paper. The detailed analysis of the torque demand during zooming was performed. Ansys workbench was used to analyze the main components of the zoom mechanism and the stray light of the system was proposed. The adjustment results show that this kind of structure can realize medium-wave infrared continuous zooming, and the the amount of optical axis shaking during zooming is less than 0.3mrad, which meets the design requirements, and the proposed stray light suppression method effectively suppresses the system's spurious radiation and improves the lens's imaging quality; impact and vibration simulation show that the strength and stiffness of the structure meet the requirements of the mechanical environment, and the imaging system has stable performance.
When the aerial camera photograph，a variety of image motion is caused by prior to the flight, pitching, rolling and vibration and other reasons，thus leading to the existence of relative motion of the illuminated objects in the focal plane of a photosensitive medium, the image is blured，and the imaging quality of the camera is seriously affected. Various causes of image motion and effects on image is analyzed by this paper,the necessity of image motion compensation is expounded. By analyzing existed methods of image motion compensation ,and on this basis, a new multi degree of freedom motion compensation method is designed,through the parallel mechanism motion,for image motion compensation by optical image motion compensation principle，a variety of airborne camera to take pictures of the image motion also can be eliminated.
This paper proposed a new algorithm of inter-frame filtering in IR image based on threshold value for the purpose of solving image blur and smear brought by traditional inter-frame filtering algorithm. At first, it finds out causes of image blur and smear by analyzing general inter-frame filtering algorithm and dynamic inter-frame filtering algorithm, hence to bring up a new kind of time-domain filter. In order to obtain coefficients of the filter, it firstly gets difference image of present image and previous image, and then, it gets noisy threshold value by analyzing difference image with probability analysis method. The relationship between difference image and threshold value helps obtaining the coefficients of filter. At last, inter-frame filtering method is adopted to process pixels interrupted by noise. The experimental result shows that this algorithm has successfully repressed IR image blur and smear, and NETD tested by traditional inter filtering algorithm and the new algorithm are respectively 78mK and 70mK, which shows it has a better noise reduction performance than traditional ones. The algorithm is not only applied to still image, but also to sports image. As a new algorithm with great practical value, it is easy to achieve on FPGA, of excellent real-time performance and it effectively extends application scope of time domain filtering algorithm.