A method for determining the best focal plane of a high-resolution optical remote sensing satellite camera

Abstract

A method for determining the optimal focal plane of a high-resolution optical remote sensing satellite camera, selects a reference image and an image to be detected, calculates the block standard deviation and gradient of the reference image and the image to be detected, respectively, and calculates the image index scale factor accordingly, according to the The scale factor determines whether the satellite camera is in the plane of best focus. After determining that the satellite camera is defocused, start the defocusing work, select the image to be detected under each focal plane during the focusing process, and then use the method of the present invention to calculate the image index scale factor, when the image index scale factor under a certain focal plane is greater than 0.9 , that is, the focal plane at this time is considered to be the best focal plane. The method of the present invention uses the block standard deviation and image gradient to accurately obtain the texture details of the image, and judges the best focal plane based on the block standard deviation and the image gradient, which is scientific, reliable, and highly pertinent, and ensures the reference image and the image to be detected The credibility of the comparison results improves the accuracy of determining the best focal plane.

Description

technical field [0001] The invention relates to a method for determining the best focal plane of an on-orbit high-resolution optical remote sensing satellite camera, belonging to the technical field of aerospace remote sensing image processing. Background technique [0002] The remarkable feature of high-resolution satellites is their long focal length. The equivalent focal length of remote sensing satellites with a resolution better than 1 meter is generally close to 10 meters. 10 meters, 8.8 meters and 7.8 meters. When the satellite completes the in-orbit test and is delivered to the user, the focal plane of the satellite is in the best position, and the quality of the acquired image reaches the optimal level. Due to the shallow depth of focus of the telephoto camera, the satellite is more susceptible to factors such as temperature, atmospheric pressure, and stress release during orbital operation, causing the imaging plane of the camera to deviate from the focal plane, t...

AI Technical Summary

Problems solved by technology

Currently, the algorithms for analyzing the sharpness of satellite in-orbit images are not targeted. Algorithms such as image standard deviation and peak signal-to-noise ratio are generally used. The above-mentioned algorithms are all for the entire image. Lack of information, image standard deviation or peak signal-to-noise ratio is very large, which cannot accurately reflect the real texture characteristics of ground objects, and reduces the credibility of the comparison results between the reference image and the image to be detected. In addition, the existing technology uses relatively independent indicators to The best focal plane is determined, and the comprehensive evaluation of various indicators is not comprehensively used, which reduces the accuracy of determining the best focal plane

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