Efficient Airborne Oblique Image Collection

• US 20180053336A1
• Filed: 03/11/2016
• Published: 02/22/2018
• Est. Priority Date: 03/11/2015
• Status: Active Grant

• Current Assignee: James Kain, James Summerville
• Original Assignee: James Kain, James Summerville
• Inventors: Summerville, James, Kain, James
• Granted Patent: US 10,424,105 B2
• Time in Patent Office: Days
• 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 21/3826 Terrain data
• CPC Class Codes: G01C 21/3852 Data derived from aerial or satellite images
• CPC Class Codes: G01S 5/0009 Transmission of position information to remote stations involving assistance data G01S5/0236
• CPC Class Codes: G03B 15/006 Apparatus mounted on flying objects
• CPC Class Codes: G06T 15/005 General purpose rendering architectures
• CPC Class Codes: G06T 15/04 Texture mapping
• CPC Class Codes: G06T 15/205 Image-based rendering
• CPC Class Codes: G06T 17/05 Geographic models
• CPC Class Codes: G08G 5/0021 located in the aircraft
• CPC Class Codes: G08G 5/0047 Navigation or guidance aids for a single aircraft details of equipment G08G5/0017
• CPC Class Codes: G08G 5/0052 for cruising combined instruments indicating more than one navigational value G01C23/00

Abstract

A system and method for airborne oblique image collection provides a dense diversity of view aspects of a subtended scene. An onboard camera of an aircraft collects a highly overlapped set of oblique images that are well suited for preparing three dimensional meshes that model complex scenes with significant vertical relief. The aircraft is flown in a radial trajectory over a targeted observable area in order to collect the images. The radial trajectory is optimized using parameters including an altitude, a field-of-view angle, an aft edge angle, and a forward edge angle of the onboard camera, as well as an expected velocity of the aircraft. A flight management system is also employed, wherein the flight management system computes a predicted location for the aircraft using location data and a current velocity of the aircraft. The predicted location being compared to an expected location, ensuring proper navigation of the radial trajectory.

Claims

1. A method for airborne oblique image collection comprises the steps of:

providing an aircraft and a flight management system, wherein the aircraft comprises an onboard camera having a boresight oriented at a camera tilt angle with respect to a yaw axis of the aircraft;

navigating, by the aircraft, a radial trajectory over a targeted observable region;

fixating, by the aircraft, the boresight about a focal point of the targeted observable region throughout the radial trajectory;

computing, by the flight management system, a predicted location for the aircraft;

comparing, by the flight management system, the predicted location to an expected location along the radial trajectory;

instructing, by the flight management system, the aircraft to adjust a current flight path, if the predicted location does not match the expected location; and

instructing, by the flight management system, the aircraft to adhere to the current flight path, if the predicted location matches the expected location.

2. The method for airborne oblique image collection as claimed in claim 1, wherein the onboard camera observes a primary coverage area and a redundant coverage area within the radial trajectory.

3. The method for airborne oblique image collection as claimed in claim 1, wherein the focal point is fixed.

4. The method for airborne oblique image collection as claimed in claim 1, wherein the focal point traverses along a linear path throughout the radial trajectory.

5. The method for airborne oblique image collection as claimed in claim 1 further comprises the steps of:

navigating, by the aircraft, a subsequent radial trajectory over the targeted observable region; and

fixating, by the aircraft, the boresight about a subsequent focal point of the targeted observable region throughout the radial trajectory.

6. The method for airborne oblique image collection as claimed in claim 5, wherein the subsequent focal point is fixed.

7. The method for airborne oblique image collection as claimed in claim 5, wherein the subsequent focal point traverses along a subsequent linear path throughout the subsequent radial trajectory.

8. The method for airborne oblique image collection as claimed in claim 1 further comprises the steps of:

receiving, by the flight management system, location data for the aircraft and a current velocity for the aircraft.

9. The method for airborne oblique image collection as claimed in claim 1 further comprises the steps of:

calculating, by the flight management system, a predicted radius about the focal point for the aircraft;

comparing, by the flight management system, the predicted radius to an expected radius of the radial trajectory; and

instructing, by the flight management system, the aircraft to increase a bank angle, if the predicted radius is larger than the expected radius.

10. The method for airborne oblique image collection as claimed in claim 1 further comprises the steps of:

calculating, by the flight management system, a predicted radius about the focal point for the aircraft;

comparing, by the flight management system, the predicted radius to an expected radius of the radial trajectory; and

instructing, by the flight management system, the aircraft to decrease a bank angle, if the predicted radius is smaller than the expected radius.

11. The method for airborne oblique image collection as claimed in claim 1 further comprises the steps of:

calculating, by the flight management system, a predicted radius about the focal point for the aircraft;

comparing, by the flight management system, the predicted radius to an expected radius of the radial trajectory; and

instructing, by the flight management system, the aircraft to maintain a bank angle, if the predicted radius is equal to the expected radius.

12. The method for airborne oblique image collection as claimed in claim 1 further comprises the steps of:

sending, by the flight management system, a camera fire command to the onboard camera.

13. The method for airborne oblique image collection as claimed in claim 1 further comprises the steps of:

receiving, by the flight management system, the radial trajectory from a computing device.

14. The method for airborne oblique image collection as claimed in claim 1 further comprises the steps of:

providing a computing device for plotting the radial trajectory;

receiving, by the computing device, an altitude, an aft edge angle, a forward edge angle, and a field-of-view angle for the onboard camera; and

calculating, by the computing device, an expected radius for the radial trajectory using the altitude, the aft edge angle, the forward edge angle, and the field-of-view angle.

15. The method for airborne oblique image collection as claimed in claim 14 further comprises the steps of:

receiving, by the computing device, an expected velocity for the aircraft;

calculating, by the computing device, an expected bank angle for the aircraft using the expected velocity and the expected radius; and

calculating, by the computing device, the camera tilt angle using the aft edge angle, the field-of-view angle, and the expected bank angle.

16. The method for airborne oblique image collection as claimed in claim 1 further comprises the steps of:

providing a display screen for the aircraft; and

displaying, by the display screen, the radial trajectory, the predicted location, a steering error indicator, and a speed error indicator.

17. The method for airborne oblique image collection as claimed in claim 16, wherein the steering error indicator compares a bank angle for the aircraft to an expected bank angle for the aircraft.

18. The method for airborne oblique image collection as claimed in claim 16, wherein the speed error indicator compares a current velocity for the aircraft to an expected velocity for the aircraft.