A tdiccd aerial camera focal plane detection method

Abstract

The invention discloses a method for detecting the focal plane of a TDICCD aerial camera. The TDICCD is multi-level partitioned, that is, the TDICCD with the original total number of N single outputs is divided into n areas, and the number of series in each area is N / n, so that The single output of the original TDICCD is changed to n outputs; when checking the focus, a wedge-shaped optical glass is cut in front of the TDICCD to change the optical path and realize multi-focal plane position imaging, that is, each sub-region corresponds to a focal plane position, and each focal plane forms The sharpness of the image represents the degree of defocus. In this way, n focal plane positions of the same scene can be imaged in one scan, and n images can be obtained. Finally, the best result can be obtained and recorded according to the sharpness evaluation function of each region’s image. The focal plane position, after the focus inspection, cut out the wedge-shaped optical glass, and then convert the best focal plane position after cutting out from the best focal plane position recorded at the time of cutting in, so that the focal plane detection can be completed through one scanning imaging, improving Focus efficiency and accuracy.

Description

technical field [0001] The invention belongs to the technical field of aerospace imaging, and in particular relates to a focal plane detection method of a TDICCD aerial camera. Background technique [0002] In order to obtain a clear image, the TDICCD long-focus aerial camera (hereinafter referred to as the camera) usually needs to search the focal plane before aerial imaging. At present, it usually uses the autocollimation method or the traditional image method. The self-collimation focus detection method uses the hill-climbing method to search for the best focal plane position within the total focus travel. This method takes a long time to search and the convergence speed is slow. The structural independence of components and imaging components (TDICCD) will have a certain impact on the focus detection accuracy; the existing image focus detection algorithm can only perform focal plane detection by imaging multiple focal plane positions in the same scene, but the TDICCD cam...

AI Technical Summary

Problems solved by technology

The self-collimation focus detection method uses the hill-climbing method to search for the best focal plane position within the total focus travel. This method takes a long time to search and the convergence speed is slow. The structural independence of components and imaging components (TDICCD) will have a certain impact on the focus detection accuracy; the existing image focus detection algorithm can only perform focal plane detection by imaging multiple focal plane positions in the same scene, but the TDICCD camera is a A line scan camera requires a rotating mechanical structure to scan the scene during imaging, so its single scan cycle can reach the order of 3 seconds, and it takes minutes to change 20 focal plane positions for imaging

The flying speed of the aerial camera carrier aircraft is fast, and the scene changes rapidly. To ensure the imaging of the same scene, it is necessary to fix the camera's boresight target pointing. The long-term target gaze, so the existing image focus detection algorithm cannot meet the requirements of the TDICCD aerial camera

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