Video rangefinder

• US 4,591,987 A
• Filed: 07/27/1983
• Issued: 05/27/1986
• Est. Priority Date: 07/27/1983
• Status: Expired due to Fees

• Current Assignee: Kollmorgen Technologies Corporation
• Original Assignee: Kollmorgen Technologies Corporation
• Inventors: Brown, David C.
• Primary Examiner(s): Lall, Parshotam S.
• Application Number:
  US06/517,807
• Time in Patent Office: 1,035 Days
• Field of Search: 364/423, 364/458, 364/560, 364/561, 358/107, 356/1, 356/4
• US Class Current: 701/225
• CPC Class Codes: G01C 3/22 using a parallactic triangle with variable angles and a base of fixed length at, near, or formed by the object

Abstract

A system for determining range and orientation of distant objects such as a ship. By utilizing split imaging the observed height on a video monitor can be accurately determined despite movements of the image on the monitor. The observed ship can be visually identified and the true height determined from reference sources. A better comparison of data indicating the true height compared to observed height permits calculation of the range to the target ship. Split imaging can also be utilized to determine the observed length of the ship so that observed height and length data can be compared to the true height and length of the target ship to determine orientation of the target ship relative to the observer.

Claims

1. A video range system comprising:

a video monitor for displaying an image of the target being ranged;

means for creating split images of said target on said monitor with a selected separation;

input means for supplying a true dimension of said target; and

computing means for calculating target range from said true dimension and said selected separation of said split images.

2. A system according to claim 1 wherein the monitor scan lines are oriented horizontally.

3. A system according to claim 1 wherein the monitor scan lines are oriented vertically.

4. A system according to claim 1 wherein said monitor forms display frames with two interlaced fields and wherein one of said split images is formed during formation of one of said fields and the other of said split images is formed during formation of the other of said fields.

5. A system according to claim 4 wherein said split images are formed by applying a positive voltage to one of said interlaced fields and a negative voltage of the same potential as said positive voltage to the other of said interlaced fields.

6. A system according to claim 5 further comprising a potentiometer for controlling the potential of said equal but opposite positive and negative voltages.

7. A system according to claim 1 wherein said video monitor is of the type wherein the illuminated screen pixel location is controlled dlgitally.

8. A system according to claim 1 wherein said monitor forms split images with alternate frames.

9. A system according to claim 1 wherein said monitor forms split images with alternate Fields of a high resolution scan rate with at least one thousand scan lines.

10. A video system for determining orientation of a target ship comprising:

a video monitor for displaying an image of the target ship being observed;

means for creating an electrical signal proportional to the observed length of the target ship on said video monitor;

means for creating an electrical signal proportional to the observed height of the target ship on said video monitor;

input means for supplying data corresponding to the true length and height dimensions of the target ship; and

computer means for determining the orientation angle of the target ship relative to the observer from said data related to said true length and height dimensions and from said electrical signals proportional to the observed length and height of the target ship on said video monitor.

11. A system according to claim 10 further including means for creating split images of said target ship on said monitor for determining the observed length of said target ship.

12. A system according to claim 10 wherein said computing means also calculates the range of the target ship from said observed height and said data corresponding to the true height of the target.

13. A system according to claim 12 further including means for creating split images of said target for determining the observed height on said video monitor.

14. A system according to claim 13 wherein said monitor forms display frames with two interlaced fields and wherein one of said split images is formed during formation of one of said fields and the other of said split images is formed during formation of the other of said fields.

15. A system according to claim 14 wherein said split images are formed by applying a positive voltage to one of said interlaced fields and a negative voltage of the same potential as said positive voltage to the other of said interlaced fields.

16. A system according to claim 15 further comprising a potentiometer for controlling the potential of said equal but opposite positive and negative voltages.