Systems and methods for passive ranging of objects

Patent metadata

Field	Value
Publication number	US-12422250-B2
Application number	US-202117180679-A
Country	US
Kind code	B2
Filing date	Feb 19, 2021
Priority date	Feb 19, 2021
Publication date	Sep 23, 2025
Grant date	Sep 23, 2025

Abstract

Apparatus and associated methods relate to passive ranging of objects by using relative positional relation of the object to a coded aperture ranged object. A first range to a first object is determined via a coded-aperture ranging system based on a point spread function optimization of an image of the first object. The terrain surface between the first object and a second object is mapped via a 3D polarimetry system. A second range to the second object is then calculated via a range calculator based on the first range and the terrain surface between the first object and the second object.

First claim

The invention claimed is:

1. A passive-ranging system comprising:
a coded-aperture ranging subsystem that determines a first range of a first object based on a point spread function optimization of an image of the first object;
a 3D polarimetry subsystem that determines terrain surface between the first object and a second object; and
a range calculator that calculates a second range of the second object based on the first range and the terrain surface between the first object and the second object.

2. The passive-ranging system of claim 1 , wherein the coded-aperture ranging subsystem further determines a third range of the second object.

3. The passive-ranging system of claim 2 , wherein the range calculator further improves accuracy of the second range of the second object based on the third range of the second object.

4. The passive-ranging system of claim 1 , wherein the range calculator further determines a relative location of the second object from the first object based on the terrain surface between the first object and the second object.

5. The passive-ranging system of claim 4 , wherein the range calculator determines the second range of the second object further based on a geometric calculation of a delta range between the first and second objects based on the relative location determined.

6. The passive-ranging system of claim 1 , wherein the passive-ranging subsystem is configured to be carried by an airborne vehicle, the passive-ranging system further comprising:
an altimeter that determines an altitude of the airborne vehicle.

7. The passive-ranging system of claim 6 , wherein the coded-aperture ranging subsystem determines the first range of the object further based on the altitude of the airborne vehicle.

8. The passive-ranging system of claim 1 , wherein the range calculator further determines a first confidence value of the first range determined.

9. The passive-ranging system of claim 8 , wherein the range calculator further determines a second confidence value of the terrain surface determined.

10. The passive-ranging system of claim 9 , wherein the range calculator further determines a third confidence value of the second range based on the first and second confidence values.

11. A method for passive ranging of objects, the method comprising:
determining, via a coded-aperture ranging subsystem, a first range of a first object based on a point spread function optimization of an image of the first object;
determining, via a 3D polarimetry subsystem, terrain surface between the first object and a second object; and
calculating, via a range calculator, a second range of the second object based on the first range and the terrain surface between the first object and the second object.

12. The method of claim 11 , further comprising:
determining, via the coded-aperture ranging subsystem, a third range of the second object.

13. The method of claim 12 , further comprising:
improving accuracy, via the range calculator, of the second range of the second object based on the third range of the second object.

14. The method of claim 11 , further comprising:
determining, via the range calculator, a relative location of the second object from the first object based on the terrain surface between the first object and the second object.

15. The method of claim 14 , further comprising:
determining, via the range calculator, the second range of the second object further based on a geometric calculation of a delta range between the first and second objects based on the relative location determined.

16. The method of claim 11 , wherein the passive-ranging system is configured to be carried by an airborne vehicle, the method further comprising:
determining, via an altimeter, an altitude of the airborne vehicle.

17. The method of claim 16 , further comprising:
determining, via the coded-aperture ranging subsystem, the first range of the object further based on the altitude of the airborne vehicle.

18. The method of claim 11 , further comprising:
determining, via the range calculator, a first confidence value of the first range determined.

19. The method of claim 18 , further comprising:
determining, via the range calculator, a second confidence value of the terrain surface determined.

20. The method of claim 19 , further comprising:
determining, via the range calculator, a third confidence value of the second range based on the first and second confidence values.

Assignees

• Raytheon Co
• Rtx Corp

Inventors

• Wehner Justin Gordon Adams
• Mustafa Jamal Ibrahim

Classifications

• G01C7/02 Primary

  of land surfaces · CPC title

• G01B11/14 Primary

  for measuring distance or clearance between spaced objects or spaced apertures (G01B11/26 takes precedence; rangefinders G01C3/00) · CPC title