Patent ID: 7376516
Filing Date: 2008-05-20
Classification: G01C,G01S,G06T

Abstract:
1. A method of transforming surveys, the method comprising: providing a plurality of surveys, each survey having a digital project file associated with the survey; reading the project files for each survey, the project files each including a plurality of points, each point having spatial coordinates defining the point's location within a local planar coordinate system, at least two of the plurality of survey projects having point locations defined in different local coordinate systems, and, at least two of the plurality of points within each project including additional spatial coordinates defining the point's location within a global coordinate system; defining a virtual box to encompass at least one point within each of the survey projects; determining an elevation of the virtual box above a reference surface of the global coordinate system based on the elevation of the survey projects above the reference surface of the global coordinate system; defining a map projection and coordinate system for the virtual box, based on the size of the virtual box and the elevation of the virtual box to minimize differences between a measured ground distance and a computed grid distance between any two points within the virtual box; using the global coordinate pairs for the at least two points within each survey project, calculate a translation and a rotation to transform coordinates from each local planar coordinate system to the coordinate system of the virtual box without a scale adjustment; applying the translation and rotation for each local planar coordinate system to the points of any survey projects projected into that local planar coordinate system, to calculate spatial coordinates for each point in each survey project in the coordinate system of the virtual box; writing the project file including the spatial coordinates in the coordinate system for the virtual box for each point in the associated survey to a storage medium.