A Calibration Method for On-orbit Optical Distortion Parameters of a Linear Array Pushbroom Camera

Abstract

A calibration method for on-orbit optical distortion parameters of a linear array push-broom camera, the steps of which are: (1) adopt an automatic matching algorithm based on control points to collect dense and high-precision control point information; (2) establish strict imaging at each control point Geometric model; (3) Calculate the theoretical pointing vector and actual pointing vector of each control point, and establish a mathematical model for geometric correction of the orientation elements in the camera; (4) Establish a distortion polynomial model corresponding to the theoretical pointing vector and the image column number; (5) The least squares method is used to solve the error equation, and the iterative solution is used to obtain the calibration parameters of the internal optical distortion of the camera. The invention calibrates the distortion of the internal optical system of the satellite on-orbit camera by selecting a large number of high-precision ground control points. The calibration results can be used to improve the uncontrolled positioning accuracy and the controlled positioning accuracy of the satellite image, and use the internal distortion calibration parameters to determine the internal orientation elements of the camera. After correction, the internal distortion of the image is basically eliminated.

Description

technical field [0001] The invention relates to a calibration method for on-orbit optical distortion parameters of a linear array push-broom camera, which belongs to the technical field of remote sensing satellite image processing and is used for optimizing and improving the on-orbit positioning accuracy of a linear push-broom camera mounted on a remote sensing satellite and improving the internal geometric quality of the image improvement optimization. Background technique [0002] With the continuous development of space technology, satellite remote sensing imagery has become an important data source for current geospatial information services and applications, and its wide application prospects have attracted widespread attention from all over the world. Compared with the ability to obtain high-resolution satellite data a few years ago, countries around the world have been scrambling to develop their own high-resolution earth observation systems in recent years, and the s...

AI Technical Summary

Problems solved by technology

Although the geometric positioning accuracy of domestic satellites is gradually improving, compared with foreign commercial high-resolution optical remote sensing satellites such as Geoeye, WorldView, Pleiades, etc., there is still a big gap in the geometric positioning accuracy of domestic satellites, especially the internal geometric accuracy of images. It cannot meet the production requirements of orthophoto products in the fields of land resources, surveying and mapping, etc., which seriously restricts the application performance of high-resolution satellite images in my country

[0004] Affected by launch momentum, on-orbit environment and other factors, the internal geometric distortion parameters of the aerospace remote sensing optical camera have changed greatly after the orbit, and the internal parameters of the camera measured on the ground will lead to large internal distortion when used for image geometric processing. Distortion, especially the internal distortion of images far away from the main point can reach the order of 30 meters, which seriously restricts the improvement of its positioning accuracy and affects subsequent advanced applications such as image mosaic mosaic

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