Localization of a surveying instrument in relation to a ground mark
First Claim
1. A method for localizing, in relation to a mark located at a ground level, a surveying instrument having a housing including at least one camera, said method comprising:
- capturing a first image of the ground below the housing in a first camera position and orientation, said first camera position being eccentric to a vertical rotational axis of the surveying instrument;
identifying an object point corresponding to the mark in the first image;
measuring first image coordinates of the object point in the first image;
capturing a second image of the ground below the housing in a second camera position and orientation;
identifying, in the second image, the object point corresponding to the mark;
measuring second image coordinates of the object point in the second image; and
determining the height of a rotation center of the surveying instrument above the mark based on the first camera position and orientation, the first image coordinates, the second camera position and orientation, the second image coordinates, and camera calibration data.
1 Assignment
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Accused Products
Abstract
A method is disclosed for localizing a surveying instrument having a housing including at least one camera in relation to a mark located at a ground level. The method comprises the steps of capturing a first image of the ground below the housing in a first camera position and orientation, wherein the first camera position is eccentric to a vertical rotational axis of the surveying instrument, identifying an object point corresponding to the mark in the first image, measuring first image coordinates of the object point in the first image. The method further comprises the steps of capturing a second image of the ground below the housing in a second camera position and orientation, identifying in the second image, an object point corresponding to the mark, and measuring second image coordinates of the object point in the second image. The height of a rotation center of the surveying instrument above the mark is then determined based on the first camera position and orientation, the first image coordinates, the second camera position and orientation, the second image coordinates, and camera calibration data. Furthermore, a surveying instrument for performing the method is disclosed.
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Citations
21 Claims
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1. A method for localizing, in relation to a mark located at a ground level, a surveying instrument having a housing including at least one camera, said method comprising:
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capturing a first image of the ground below the housing in a first camera position and orientation, said first camera position being eccentric to a vertical rotational axis of the surveying instrument; identifying an object point corresponding to the mark in the first image; measuring first image coordinates of the object point in the first image; capturing a second image of the ground below the housing in a second camera position and orientation; identifying, in the second image, the object point corresponding to the mark; measuring second image coordinates of the object point in the second image; and determining the height of a rotation center of the surveying instrument above the mark based on the first camera position and orientation, the first image coordinates, the second camera position and orientation, the second image coordinates, and camera calibration data. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 13, 21)
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11. A method for localizing, in relation to a mark located at a ground level, a surveying instrument having a housing including at least one camera, said method comprising:
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capturing a first image of the ground below the housing in a first camera position and orientation, said first camera position being eccentric to a vertical rotational axis of the surveying instrument; identifying an object point corresponding to the mark in the first image; measuring first image coordinates of the object point in the first image; capturing a second image of the ground below the housing in a second camera position and orientation; identifying, in the second image, the object point corresponding to the mark; measuring second image coordinates of the object point in the second image; determining the height of a rotation center of the surveying instrument above the mark based on the first camera position and orientation, the first image coordinates, the second camera position and orientation, the second image coordinates, and camera calibration data; selecting a minimum distance and a maximum distance from the first camera position along an imaging ray of the mark in the first image, between which minimum distance and maximum distance the mark is located; determining, based on the maximum distance and the minimum distance, a section of the epipolar line in the second image on which the object point is located; determining whether the epipolar line is completely inside the second image; rotating, if the epipolar line is not completely inside the second image, the surveying instrument around the rotation center based on epipolar line data, the second camera position and orientation and second camera calibration data to a revised second camera position and orientation in order to obtain a new epipolar line within a revised second image; capturing the revised second image using the camera in the revised second position and orientation; and identifying, along the new epipolar line in the revised second image, the object point identified in the first image.
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14. A surveying instrument, comprising:
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at least one camera adapted to capture a first image of the ground below the housing in a first camera position and orientation and a second image of the ground below the housing in a second camera position and orientation, said first camera position being eccentric to the vertical rotational axis of the surveying instrument; an identifying unit adapted to identify an object point corresponding to a mark located at a ground level under said instrument in the captured images; a measuring unit adapted to measure first and second image coordinates of the object point in the first and second images; and a processor adapted to determine the height of a rotation center of the surveying instrument above the mark based on the first position and orientation, the first image coordinates, the second position and orientation, the second image coordinates, and camera calibration data. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification