Systems and methods of capturing large area images in detail including cascaded cameras and/or calibration features

• US 10,358,234 B2
• Filed: 04/30/2013
• Issued: 07/23/2019
• Est. Priority Date: 04/11/2008
• Status: Active Grant

• Current Assignee: NearMap Pty Ltd.
• Original Assignee: NearMap Pty Ltd.
• Inventors: Nixon, Stuart William
• Primary Examiner(s): Volentine, Rebecca A
• Application Number:
  US13/873,818
• Publication Number:
  US 20150353205A1
• Time in Patent Office: 2,275 Days
• CPC Class Codes: B64D 47/08 Arrangements of cameras
• CPC Class Codes: B64G 1/1021 Earth observation satellites
• CPC Class Codes: B64G 1/1028 using optical means for mapping, surveying or detection, e.g. of intelligence
• CPC Class Codes: B64U 20/87 Mounting of imaging devices, e.g. mounting of gimbals
• CPC Class Codes: G01C 11/025 by scanning the object
• CPC Class Codes: H04N 23/45 for generating image signals from two or more image sensors being of different type or operating in different modes, e.g. with a CMOS sensor for moving images in combination with a charge-coupled device [CCD] for still images
• CPC Class Codes: H04N 23/698 for achieving an enlarged field of view, e.g. panoramic image capture
• CPC Class Codes: H04N 25/41 Extracting pixel data from a plurality of image sensors simultaneously picking up an image, e.g. for increasing the field of view by combining the outputs of a plurality of sensors
• CPC Class Codes: H04N 7/181 for receiving images from a plurality of remote sources

Abstract

Systems and methods are disclosed relating to acquisition of images regarding large area objects or large areas. In one exemplary embodiment, there is provided a method of obtaining or capturing, via a first system that includes one or more first image capturing devices, overview images, wherein the overview images depict first areas, as well as obtaining or capturing, via a second system that includes a plurality of image capturing devices, detail images characterized as being related to each other along an image axis. Moreover, the detail images may depict second areas that are subsets of the first areas, they may be arranged in strips parallel to the image axis, and they may have a higher resolution than corresponding portions of the first images.

Claims

1. A method of creating a photomap of a survey area, the method comprising:

(a) flying an aircraft above the survey area along a set of substantially parallel flight lines;

(b) capturing, during flight and via at least one overview camera carried by the aircraft, a sequence of overview images, each overview image depicting an overview area of the survey area, consecutive overview areas along each flight line overlapping longitudinally by a first overlap proportion, adjacent overview areas associated with adjacent flight lines overlapping laterally;

(c) capturing, during flight and via a first array of detail cameras carried by the aircraft, a sequence of detail image strips, each detail image strip comprising at least one detail image, each detail image depicting at least a portion of an overview area, each detail image having a higher resolution than a resolution of the overview image corresponding to the overview area, consecutive detail image strips along each flight line overlapping longitudinally by a second overlap proportion, the second overlap proportion being smaller than the first overlap proportion, adjacent detail image strips associated with adjacent flight lines overlapping laterally, adjacent detail images within each strip overlapping laterally;

(d) identifying, in a plurality of the overview images and detail images, common features corresponding to common ground points;

(e) generating, via bundle adjustment and from the identified ground points, an exterior orientation associated with each detail image; and

(f) merging, based on at least some of the generated exterior orientations, at least some of the detail images to create the photomap.

2. The method of claim 1, wherein the first array of detail cameras provides a vertical view, and the photomap provides a vertical view.

3. The method of claim 2 further comprising capturing, via a second array of detail cameras, a sequence of oblique detail image strips, and creating, from the oblique detail image strips, an oblique photomap of the survey area.

4. The method of claim 1, wherein the aircraft is selected from the group comprising a single-engine manned aircraft and an unmanned aerial vehicle (UAV).

5. A system for creating a photomap of a survey area, the system comprising:

(a) an aircraft;

(b) at least one overview camera carried by the aircraft;

(c) a first array of detail cameras carried by the aircraft; and

(d) a computer system, wherein

the aircraft is operable to be flown above the survey area along a set of substantially parallel flight lines;

the at least one overview camera is configured to capture, during flight, a sequence of overview images, each overview image depicting an overview area of the survey area, consecutive overview areas along each flight line overlapping longitudinally by a first overlap proportion, adjacent overview areas associated with adjacent flight lines overlapping laterally;

the first array of detail cameras is configured to capture, during flight, a sequence of detail image strips, each detail image strip comprising at least one detail image, each detail image depicting at least a portion of an overview area, each detail image having a higher resolution than a resolution of the overview image corresponding to the overview area, consecutive detail image strips along each flight line overlapping longitudinally by a second overlap proportion, the second overlap proportion being smaller than the first overlap proportion, adjacent detail image area strips associated with adjacent flight lines overlapping laterally, adjacent detail image second areas within each strip overlapping laterally, and

the computer system is configured to;

(i) identify, in a plurality of the overview images and detail images, common features corresponding to common ground points,

(ii) generate, via bundle adjustment and from the identified ground points, an exterior orientation associated with each detail image; and

(iii) merge, based on at least some of the generated exterior orientations, at least some of the detail images to create the photomap.

6. The system of claim 5, wherein the first array of detail cameras provides a vertical view, and the photomap provides a vertical view.

7. The system of claim 6, further comprising a second array of detail cameras configured to capture a sequence of oblique detail image strips, wherein the computer system is further configured to create, from the oblique detail image strips, an oblique photomap of the survey area.

8. The system of claim 5, further comprising an enclosure within which the cameras are mounted.

9. The system of claim 8, wherein each camera is removably mounted within the enclosure.

10. The system of claim 8, wherein the enclosure is adapted to be mounted to the exterior of the aircraft.

11. The system of claim 8, wherein the enclosure is adapted to be removably mounted to the exterior of the aircraft.

12. The system of claim 5, further comprising a plurality of data storage devices, each data storage device associated with a respective one of the cameras and configured to store images captured by the camera.

13. The system of claim 12, wherein each data storage device is a flash memory storage device.

14. The system of claim 5, wherein the aircraft is selected from the group comprising a single-engine manned aircraft and an unmanned aerial vehicle (UAV).