Photogrammetric networks for positional accuracy

• US 8,264,537 B2
• Filed: 09/28/2007
• Issued: 09/11/2012
• Est. Priority Date: 09/28/2007
• Status: Active Grant

• Current Assignee: The Mainz Group, LLC
• Original Assignee: The Mainz Group, LLC
• Inventors: Westrick, William A., Apter, Elena V.
• Primary Examiner(s): Chang, Jungwon
• Application Number:
  US11/864,515
• Publication Number:
  US 20090086020A1
• Time in Patent Office: 1,810 Days
• Field of Search: 348/115, 348/135, 348/140, 348/169, 382/154, 382/100
• US Class Current: 348/140
• CPC Class Codes: G01C 11/02 Picture taking arrangements specially adapted for photogrammetry or photographic surveying, e.g. controlling overlapping of pictures
• CPC Class Codes: G01C 11/04 Interpretation of pictures
• CPC Class Codes: G01C 7/04 involving a vehicle which moves along the profile to be traced
• CPC Class Codes: G01S 19/47 the supplementary measurement being an inertial measurement, e.g. tightly coupled inertial
• CPC Class Codes: G06T 7/70 Determining position or orientation of objects or cameras camera calibration G06T7/80
• CPC Class Codes: G06T 7/73 using feature-based methods
• CPC Class Codes: H04N 7/18 Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast

Abstract

The present invention involves a surveying system and method which determines the position of a object point using two images. First, at least two reference points appearing on the two images are correlated. Then the position of the object point is determined based on the two images and the two reference points.

Claims

1. A surveying system for determining the location of an object point from images, said surveying system comprising:

two image gathering devices coupled at a known relative distance, each said image gathering device adapted to generate an image;

a global positioning system providing an absolute position of a first capture point; and

a location calculator, said location calculator having a plurality of instructions enabling said location calculator to correlate at least two reference points appearing on two images obtained with the two image gathering devices at the first capture point with reference points appearing on images obtained at a second capture point to obtain correlated reference points, and to determine the position of the object point based on the correlated reference points and the absolute position of the first capture point.

2. The surveying system of claim 1 further comprising an inertial navigation system, wherein the position of the object point is determined taking into account a direction signal from the inertial navigation system.

3. The surveying system of claim 1, wherein the location calculator determines a first position of a correlated point based on the absolute position of the first capture point and the images obtained at the first capture point, determines a second position of the correlated point based on the absolute position of the second capture point and the images obtained at the second capture point, and determines the position of the object point based on the first position of the correlated point and the second position of the correlated point.

4. In a surveying system, a method of determining the position of an object point, said method comprising the steps of:

obtaining an absolute position of a first capture point with a global positioning system;

correlating at least two reference points appearing on two images obtained at the first capture point with reference points appearing in second images obtained at a second capture point to obtain correlated reference points; and

determining the position of the object point based on the correlated reference points and the absolute position of the first capture point.

5. The method of claim 4 further comprising the step of identifying the two reference points.

6. The method of claim 5 wherein said step of identifying is accomplished by one of manual observation, strip mapping, depth mapping, and ray mapping.

7. The method of claim 4 wherein said step of correlating is accomplished by one of mesh correlation, sequence correlation, and orientation aware weighing.

8. The method of claim 4 further comprising the step of determining the location of a correlation point by weighing the corresponding reference points obtained at the first capture point and at the second capture point based on an error function.

9. The method of claim 8 further comprising the step of using the location of the correlation point to correct the location of the object point.

10. The method of claim 8 wherein said step of determining the location of a correlation point is accomplished by one of ramp averaging and spline averaging.

11. The method of claim 4 wherein said step of determining the position of the object point is accomplished by one of reference correlation, 3 point correlation, and RMS correlation.

12. The method of claim 4, further comprising:

determining a first position of a correlated point based on the absolute position of the first capture point and the images obtained at the first capture point,

determining a second position of the correlated point based on the absolute position of the second capture point and the images obtained at the second capture point, and

determining the position of the object point based on the first position of the correlated point and the second position of the correlated point.

13. A machine-readable program storage device for storing encoded instructions for a method of determining the location of an object point, said method comprising the steps of:

obtaining an absolute position of a first capture point from a global positioning system;

obtaining images from two image gathering devices coupled at a known relative distance;

correlating at least two reference points appearing on two images obtained at the first capture point with reference points appearing on images obtained at a second capture point to obtain correlated reference points; and

determining the position of the object point based on the correlated reference points and the absolute position of the first capture point.

14. The machine-readable program storage device of claim 13 wherein said method further comprises the step of identifying at least two reference points.

15. The machine-readable program storage device of claim 14 wherein said method has said step of identifying being accomplished by one of strip mapping, depth mapping, and ray mapping.

16. The machine-readable program storage device of claim 13 wherein said method has said step of correlating being accomplished by one of mesh correlation, sequence correlation, and orientation aware weighing.

17. The machine-readable program storage device of claim 13 wherein said method further comprises the step of determining the location of a correlated reference point by weighing the corresponding reference points obtained at the first capture point and at the second capture point based on an error function.

18. The machine-readable program storage device of claim 17 wherein said method includes using the location of the correlation point to correct the location of the object point.

19. The machine-readable program storage device of claim 17 wherein said method includes said step of determining the location of correlation points being accomplished by one of ramp averaging and spline averaging.

20. The machine-readable program storage device of claim 13 wherein said method includes said step of determining the position of the object point being accomplished by one of reference correlation, 3 point correlation, and RMS correlation.