The Mtf Of The Low-resolution Satellite Imaging System On-orbit Detection Method

It is a high-performance technology to get information from satellite remote sensing images, it plays an important role in various fields of socio-economic. When the satellite get on it's orbit, because of the Astor-radiation, they own components get aging and other affecters, its performance will gradually decline, and the remote sensing images' quality will also reduce. So it is necessary to know how the system's performance changes with time.Modulation Transfer Function (MTF) is an essential parameter in satellite imaging system, it is a useful method to measuring MTF directly from satellite image, and this research has also become a hot field in at home and abroad.This paper research on mid-low spatial resolution satellite imaging system's MTF on-orbit measurement, based on the traditional straight-edge method. For the mid-low spatial resolution satellite remote sensing image, it is very difficult to obtain a perfect straight edge object, so how to measure the MTF of the mid-low spatial resolution satellite on orbit is a hard task. This paper brings out a new advance method to solve this problem. The method use techniques of fitting curve edge with polynomial, approaching the edge spread function (ESF) by Fermi function, and calculating the function coefficients with simulated annealing algorithm. The algorithm for computing MTF of remote sensing image with curve edge is designed, which provide an effective measure method in mid-low spatial resolution satellite on orbit.Whether the method of MTF Measurement is reliable need an objective evaluation. This paper uses the MTF Simulation Method to evaluate the algorithm, analysis how the gray value affect the experimental results, at the same time, an improved method about the estimate standard is achieved, it use the area which is surrounded by MTF curve to express the error, this method has been achieved and has good experimental results.