Research On IRFPA Imaging System Dynamic Range Adaptive Adjust Technology

As the development of the infrared imaging technology, infrared focal plane arrays (IRFPA) imaging system are applied extensively in some field. Duo to the application range is extended, more performance parameters are expected. When the targets that have the very large variation range of infrared radiation are detected, it is vital that the imaging systems have the same large dynamic range. If the dynamic range of the imaging system can not oversize the targets', the system can not detect overall information of the target. So it is very important to widen the dynamic range of the imaging system for the target detection.For this reason, the domestic and foreign development situation of the research direction is expounded in the paper, and the constituents and the operating principle of IRFPA imaging system are analyzed, several methods of widening the dynamic range are summarized. By the comparison of these methods, the method that dynamic range adaptive adjust is put forwarded, namely the dynamic range of imaging system is adjusted by adaptive adjusting the integration time.In order to approve the feasibility of the method, the influence to the imaging system performance is analyzed, when the integration time is changed. And some experiment data is obtained.In the implementation procedure of the method, the main contents are as follows:(1)Obtain the adjust witness: Because the dynamic range will be adjusted, a adjust witness must be selected. This can control the change of the integration reasonable. The image processing method is applied to the obtained images.(2)Achieve the adjust algorithm: The adjust algorithm is a key part of the dynamic range adaptive adjust technology. The LMS adaptive filter technology is used in the algorithm. Its merit is that reducing noise and improving the system stability.(3)Solve the non-uniformity problem: When the integration time changed, the non-uniformity of the system will change too, so a solving way must be put forward, else if the imaging quality will be influenced. A simple method is put forward in this paper.At last, the experimentation about the method is made, the feasibility of the dynamic range adaptive adjust technology is proved by the experiment images.