Elevation angle estimating device and method for user terminal placement

• US 9,995,572 B2
• Filed: 03/31/2015
• Issued: 06/12/2018
• Est. Priority Date: 03/31/2015
• Status: Active Grant

• Current Assignee: WorldVu Satellites Limited
• Original Assignee: WorldVu Satellites Limited
• Inventors: Ni, Melvin S.
• Primary Examiner(s): Ratcliffe, Luke D
• Application Number:
  US14/674,363
• Publication Number:
  US 20160290793A1
• Time in Patent Office: 1,169 Days
• CPC Class Codes: G01B 11/26 for measuring angles or tapers; for testing the alignment of axes
• CPC Class Codes: G01C 1/00 Measuring angles
• CPC Class Codes: G01C 15/002 Active optical surveying means optical plumbing G01C15/105
• CPC Class Codes: G02B 17/08 Catadioptric systems used in non-imaging applications G02B19/00
• CPC Class Codes: G02B 27/32 Fiducial marks and measuring scales within the optical system

Abstract

A device and method for estimating the elevation angle of one or more objects surrounding a user terminal include a convex image-reflecting surface, a transparent sighting surface disposed above the convex image-reflecting surface, and an elevation limit marking formed on or in the sighting surface. The elevation limit marking generates a reflected image in the convex image-reflecting surface that defines an elevation angle above a horizon of the earth that the one or more objects in a field of view of the convex image-reflecting surface must remain below so that the user terminal has an unobstructed view of the sky in all azimuthal directions.

Claims

1. A device for estimating an elevation angle of one or more objects surrounding a user terminal, the device comprising:

a convex image-reflecting surface;

a transparent sighting surface disposed above the convex image-reflecting surface; and

an elevation limit marking formed on or in the transparent sighting surface;

wherein the elevation limit marking generates a reflected image in the convex image-reflecting surface that defines the elevation angle above a horizon of the earth that the one or more objects in a field of view of the convex image-reflecting surface must remain below so that the user terminal has an unobstructed view of the sky in all azimuthal directions.

2. The device of claim 1, wherein the elevation angle defined by the elevation limit marking comprises a maximum elevation angle.

3. The device of claim 1, further comprising at least a second elevation limit marking formed on or in the transparent sighting surface that generates a reflected image in the convex image-reflecting surface that defines at least a second elevation angle above the horizon of the earth that the one or more objects in the field of view of the convex image-reflecting surface must remain below so that the user terminal has the unobstructed view of the sky in all the azimuthal directions.

4. The device of claim 1, wherein the elevation limit marking comprises a circle.

5. The device of claim 1, wherein the elevation limit marking is comprises concentric circles.

6. The device of claim 1, further comprising a boresight marking formed on or in the transparent sighting surface and axially aligned with a pole of the convex image-reflecting surface.

7. The device claim 6, wherein the boresight marking comprises a crosshair.

8. The device of claim 1, wherein a reflected image of the one or more objects in the field of view of the convex image-reflecting surface is formed behind the convex image-reflecting surface.

9. The device of claim 8, wherein if the reflected image of the one or more objects is substantially outside the reflected image of the elevation limit marking, the one or more objects are estimated to be below the elevation angle.

10. The device of claim 8, wherein if a portion of the reflected image of the one or more objects is substantially inside the reflected image of the elevation limit marking, the one or more objects are estimated to be above the elevation angle.

11. The device of claim 1, wherein the convex image-reflecting surface comprises a convex mirror.

12. The device of claim 1, wherein the transparent sighting surface comprises a transparent screen.

13. The device of claim 1, further comprising a tubular spacer extending between the transparent sighting surface and the convex image-reflecting surface.

14. The device of claim 1, wherein the device comprises a pre-assembled integral unit.

15. The device of claim 1, wherein the device comprises an unassembled kit that a user assembles.

16. A user terminal comprising a housing, an antenna disposed within the housing, and the device of claim 1 disposed on or embedded in an outer surface of the housing.

17. A method for estimating an elevation angle of one or more objects surrounding a user terminal, the method comprising:

placing a convex image-reflecting surface on or adjacent to the user terminal;

viewing the convex image-reflecting surface through a transparent sighting surface having an elevation limit marking formed on or in the transparent sighting surface, the elevation limit marking generating a reflected image in the convex image-reflecting surface that defines the elevation angle above a horizon of the earth that the one or more objects in a field of view of the convex image-reflecting surface must remain below so that a user terminal has an unobstructed view of the sky in all azimuthal directions; and

observing whether a reflected image of the one or more objects is substantially outside, or a portion thereof is substantially inside, the reflected image of the elevation limit marking, wherein if the reflected image of the one or more objects is substantially outside the reflected image of the elevation limit marking, the one or more objects are estimated to be below the elevation angle, and if a portion of the reflected image of the one or more objects is substantially inside the reflected image of the elevation limit marking, the one or more objects are estimated to be above the elevation angle.

18. The method of claim 17, wherein prior to observing whether a reflected image of the one or more objects is substantially outside or a portion thereof is substantially inside the reflected image of the elevation limit marking, further comprising:

focusing on a boresight marking formed on or in the transparent sighting surface; and

axially aligning the boresight marking with a reflected image of the boresight marking formed within the convex image-reflecting surface.

19. A method for estimating an elevation angle of one or more objects surrounding a user terminal, the method comprising:

generating a reflected image of an elevation angle limit marking in a convex image-reflecting surface placed on or adjacent to the user terminal, the elevation angle limit marking defining the elevation angle above a horizon of the earth that the one or more objects in a field of view of the convex image-reflecting surface must remain below so that a user terminal has an unobstructed view of the sky in all azimuthal directions; and

generating a reflected image of the one or more objects in the convex image-reflecting surface, wherein if the reflected image of the one or more objects is substantially outside the reflected image of the elevation limit marking, the one or more objects are estimated to be below the elevation angle, and if a portion of the reflected image of the one or more objects is substantially inside the reflected image of the elevation limit marking, the one or more objects are estimated to be above the elevation angle.

20. The method of claim 19, wherein the generating of the reflected image of the elevation angle limit marking is performed with a transparent sighting surface having an elevation limit marking formed on or in the transparent sighting surface.