Multi-area array aerial camera platform calibration method with constraint condition

Abstract

The invention discloses a multi-area array aerial camera platform calibration method with a constraint condition. The method includes: employing a data acquisition strategy of multiple cross flying camera station exposure to acquire multiple groups of sub-images with an adjacent virtual image overlap degree of more than 80%; making use of the control point of a ground calibration field to calculate a photographing centre distance of sub-cameras and a sub-camera line element; during aerotriangulation, conducting bundle block adjustment, according to the control point coordinate, the connection points among matched sub-images, and the external orientation element initial value, establishing a model through a collinearity equation, adopting the photographing centre distance of the sub-cameras as a given value, i.e. taking the sub-camera line element constant as the constraint condition, and taking platform calibration parameters as a whole to perform calculation to solve the angle elements in the external orientation elements of the sub-images. According to the calibration method, a lot of uniformly distributed connection points are matched, precision of the platform calibration parameters is improved through the constraint condition, higher stitching precision of the generated virtual images can be guaranteed, and the mapping precision can be higher.

Description

technical field [0001] The invention relates to the technical field of aerial photogrammetry, in particular to a multi-array aerial camera platform calibration method with constraints. Background technique [0002] Aerial cameras have been successfully used in the world for decades. In the past two decades, the data acquisition means of photogrammetry has gradually developed towards digital cameras. Considering two aspects of the current manufacturing process and economic factors, a single digital camera cannot replace the traditional film aerial camera. In order to use more economical means to meet the needs of large-format aerial photography, some companies have adopted multi-lens combination cameras. At present, the international mainstream multi-lens combination digital aerial camera products mainly include UltraCam series large-format digital aerial cameras, DMC large-format digital aerial cameras, and domestic SWDC-4 and TOPDC-4 large-format digital aerial cameras. ...

AI Technical Summary

Problems solved by technology

[0006] Disadvantages of the existing technology: the cross-overlap area method platform calibration requires uniformly distributed connection points in the overlap area of ​​the four sub-images, and the number is not less than 30-50

This method cannot accurately calculate the platform calibration parameters when the overlapping area of ​​the sub-images is small, or the image texture in the overlapping area is poor, and the ideal number of evenly distributed connection points cannot be matched.

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