HIGH ACCURACY SURVEY GRADE GIS SYSTEM

• US 20070050143A1
• Filed: 08/22/2006
• Published: 03/01/2007
• Est. Priority Date: 08/23/2005
• Status: Active Grant

• Current Assignee: Robert Jones
• Original Assignee: Robert Jones
• Inventors: Jones, Robert
• Granted Patent: US 7,376,516 B2
• Time in Patent Office: Days
• US Class Current: 702/5
• CPC Class Codes: G01C 15/00 Surveying instruments or accessories not provided for in groups G01C1/00 - G01C13/00
• CPC Class Codes: G01S 19/04 providing carrier phase data
• CPC Class Codes: G06T 17/05 Geographic models
• CPC Class Codes: G06T 19/20 Editing of 3D images, e.g. changing shapes or colours, aligning objects or positioning parts
• CPC Class Codes: G06T 2219/2016 Rotation, translation, scaling
• CPC Class Codes: G06T 3/02 Affine transformations for image registration G06T3/147; for image mosaicing G06T3/4038

Abstract

A method of coordinating surveys of different origins and which may be projected into different coordinate systems. The method provides a translation and rotation of the surveys to be coordinated without disturbing the internal geometry of each survey. A geographic information system including a procedure for coordinating surveys of different origins and/or which surveys which projected in different coordinate systems.

Claims

1. A method of transforming surveys of different parcels of land into a common grid coordinate system, the method comprising:

providing at least two surveys, each survey including a plurality of points denoting a location on the face of the earth with the locations on the face of the earth expressed in different coordinate systems;

selecting the common grid coordinate system so that a maximum difference between grid distances and ground distances is reduced to an insignificant amount over the area encompassing the surveys to be transformed;

associating at least two points in each survey with points that represent the same physical location on earth in the common grid coordinate system, wherein the association of points representing the same physical points on the surface of the earth but in different coordinate systems defines a translation and rotation to be applied to each survey; and

translating and rotating each survey to perform a non-scaled transformation of each survey into the common grid coordinate system.

2. The method of claim 1, wherein the method is carried out within an automated geographic information system.

3. The method of claim 1, wherein at least one of the surveys is originally projected in state plane coordinates.

4. The method of claim 1, wherein the association of points within at least one of the surveys is made by use of a high accuracy survey relative to at least one known control point outside of the survey.

5. The method of claim 4, wherein a minimum of two known control points outside of the survey are used to associate points.

6. The method of claim 4, wherein the high accuracy survey is carried out with global positioning system receivers.

7. The method of claim 4, wherein the at least one control point outside of the survey is a CORS control point.

8. The method of claim 4, wherein the association of points within all of the surveys is made by use of global positioning system receivers, at least two known control points are used to associate the points, and at least one of the control points used is a CORS control point.

9. The method of claim 1, wherein the common grid coordinate system is selected so that the maximum difference between a computed grid distance between any two points in any of the surveys transformed into the common grid coordinate system and a distance measured on the ground between those same two points is less than one part in thirty thousand.

10. The method of claim 9, wherein the maximum difference between a computed grid distance between the two points and a distance measured on the ground between those same two points is less than one part in two hundred thousand.

11. A geographic information system comprising:

a transformer to transform surveys of different parcels of land into a common grid coordinate system by associating all of a plurality of points in each survey with at least two points in that survey that include coordinates in a global coordinate system, the transformer including;

a selector to select the common grid coordinate system encompassing an area containing the parcels, wherein the common grid coordinate system is defined by a map projection selected to reduce the difference between grid distances and ground distances to an insignificant amount over the area; and

,

a calculator to calculate a non-scaled transformation including a translation and a rotation for the plurality of points in each survey based on the at least two points with global coordinates;

wherein the non-scaled transformation allows each of the points of each of the surveys to be expressed in the common grid coordinate system.

12. The geographic information system of claim 11, wherein the points within each survey that include global coordinates have the global coordinates determined by a satellite based positioning system.

13. The geographic information system of claim 12, wherein at least one of the points with global coordinates in each survey are located relative to a ground based reference station.

14. The geographic information system of claim 11, wherein the points within at least one of the surveys are expressed in a state plane coordinate system prior to the transformation into the common grid coordinate system.

15. The geographic information system of claim 11, wherein the points within at least one of the surveys are expressed in a county coordinate system prior to the transformation into the common grid coordinate system.

16. The geographic information system of claim 11, wherein the common grid coordinate system is defined by a map projection selected to provide a maximum difference between distances between any two points computed from coordinates in the common grid coordinate system and distances measured on the ground between the same two points is less than one part in thirty thousand.

17. The geographic information system of claim 16, wherein the map projection of the common grid coordinate system are selected to provide a maximum difference between computed and ground distances of one part in two hundred thousand.

18. The geographic information system of claim 11, wherein the calculator utilizes at least three points including global coordinates within each survey to define the translation and rotation to be applied to each of the points within the survey to transform the original coordinates of the survey to the local grid coordinate system, and the calculator includes a least squares calculation to define the non-scaled translation and rotation.

19. A method of transforming surveys, the method comprising:

providing a plurality of surveys, each survey having a digital project file associated with the survey, and the project files for each survey 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.

20. The method of claim 19, wherein the differences between measured ground distance and calculated grid distance between any two points in the coordinate system of the virtual box are less than one part in thirty thousand.

21. The method of claim 19, wherein the differences between measured ground distance and calculated grid distance between any two points in the coordinate system of the virtual box are less than one part in two hundred thousand.

22. The method of claim 19, wherein the map projection of the virtual box is one of a transverse mercator projection or a Lambert conformal conic projection.

23. A geographic information system comprising:

a database including a plurality of survey project files, each project file including a plurality of points, each point including at least a first set of coordinates in a local coordinate system of the survey project, at least two points within each project also having coordinates in a global coordinate system;

means for defining a virtual box encompassing at least one point from each of a plurality of survey project files, calculating an elevation for the virtual box and determining a coordinate system for the virtual box based on the elevation of the virtual box;

means for defining a coordinate transformation for each survey project from the local coordinate system of the survey project to the coordinate system of the virtual box, each coordinate transformation including only a translation and a rotation to be applied to the local coordinates of the project file, with no scaling;

means for applying the coordinate transformation for each survey project to the points within that survey project to calculate new coordinates for each point in the survey project, the new coordinates defined in the coordinate system of the virtual box.

24. The geographic information system of claim 23, wherein at least three points within a first survey project include coordinates in a global coordinate system, and the means for determining the coordinate transformation for the first survey project into the coordinate system of the virtual box includes a least squares computation.

25. The geographic information system of claim 23, wherein the means for defining the virtual box, the means for defining the coordinate transformation, and the means for applying the coordinate transformation to each survey project are automated processes within the geographic information system.

26. The geographic information system of claim 23, wherein the differences between measured ground distance and calculated grid distance between any two points in the coordinate system of the virtual box are less than one part in thirty thousand.

27. The geographic information system of claim 26, wherein the differences between measured ground distance and calculated grid distance between any two points in the coordinate system of the virtual box are less than one part in two hundred thousand.