Research On Microscanning Theory And Technology Of Thermal Microscopic Imaging System

From repeating sampling of the same scene, the optical microscanning technology can improve the spatial resolution of the imaging system without changing the structure of the detector. The thermal microscopic imaging system always has low spatial resolution. In order to obtain a system with high spatial resolution, we put forward a new method to solve the technical problem of optical microscanning equipment based on the working principle of optical microscanning thermal microscopic imaging system.Firstly, noise equivalent temperature difference(NETD) model and noise equivalent eradiation difference(NEED) model of thermal microscopic imaging system were researched. Based on the NETD and NEED models, we explored the relationship of them before and after adding the optical microscanning equipment to the thermal microscopic imaging system. Then the feasible method of improving the system performance was proposed based on the theory.Secondly, in order to use the microscanning technology perfectly in the thermal microscopic imaging system, the zero of microscanning is very important and should be determined. We proposed a new adaptive zero calibration method. In this method image registration algorithm was used to calculate the micro-displacement, then the zero was adaptively calibrated based on the micro-displacement and geometric principle. Using telescopic thermal image to simulate the real system, different reconstruction methods were adopted to construct the simulation image and the real thermal microscopic image before and after adaptive zero calibration. The results showed that the adaptive zero calibration method was effective.Finally, after completing the adaptive calibration of zero position in the system, the calibration of the other three microscanning positions was also very important in2×2micro-scan mode. Based on zero adaptive calibration, we use the geometric principle and image registration method to calibrate the other positions, and then we proposed a method to calibrate all the microscanning positions adaptively. The simulation and experiment shows that the microscanning method in this paper played an important role in thermal microscopic imaging system, which can significantly improve the quality of oversampling reconstruction image and improve spatial resolution of the system. This method can also be used in other photoelectric imaging system.