System for topographic mapping from remotely sensed images
First Claim
1. A method of generating a digital elevation model of terrain comprising generating a first image of said terrain, generating a second image of said terrain at a different viewing angle than said first image, determining matching points in said first and second images, defining a registration matching equation which matches points from said first image to said second image, said matching equation including coefficients, determining from said matching points with a data processor the coefficients of said registration matching equation, said matching equation having a height term which varies with the terrain elevation in the coordinates of one of said images, correcting with said data processor said height term to correspond to the elevation of said terrain in the coordinates of one of said images, and rotating with said data processor the elevation of said terrain into the coordinates of a ground plane corresponding to said terrain to provide a digital elevation model.
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Abstract
In a method for generating a model of terrain, images of the terrain are generated at different angles. Matching points in the images are identified and from these matching points, the coefficients of a registration mapping equation are determined. A height term of the registration matching equation is corrected for scaling and shear into an elevation term in the coordinates of one of the images. The elevation is rotated into the coordinates of the ground plane of the terrain to provide a digital elevation model of the terrain. Interpolation is carried out through the digital elevation model to provide a three-dimensional model of the terrain. In a system for measuring the accuracy of a registration mapping equation, first and second images are generated from a digital elevation model. The registration mapping equation being tested is applied to the images to generate an estimated digital matching function which is compared with the actual registration matching function for the two images.
67 Citations
10 Claims
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1. A method of generating a digital elevation model of terrain comprising generating a first image of said terrain, generating a second image of said terrain at a different viewing angle than said first image, determining matching points in said first and second images, defining a registration matching equation which matches points from said first image to said second image, said matching equation including coefficients, determining from said matching points with a data processor the coefficients of said registration matching equation, said matching equation having a height term which varies with the terrain elevation in the coordinates of one of said images, correcting with said data processor said height term to correspond to the elevation of said terrain in the coordinates of one of said images, and rotating with said data processor the elevation of said terrain into the coordinates of a ground plane corresponding to said terrain to provide a digital elevation model.
- View Dependent Claims (2, 3, 4, 5, 7, 8, 9, 10)
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10. A method as recited in claim 1 wherein said height term is related to the elevation in one of said images in accordance with a predetermined function and wherein said height term is corrected to correspond to the elevation in accordance with said predetermined function.
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6. A system for measuring the accuracy of a registration mapping equation comprising means for providing a digital elevation model of terrain, means responsive to said digital elevation model to generate images of said digital elevation model at first and second viewing angles, means to apply a registration mapping equation to said first and second images to generate an estimated registration mapping function, means to produce the actual registration mapping function for said images, and means to generate a quantitative measurement of the difference between said estimated registration mapping function and said actual registration mapping function.
Specification