Passive ranging tail warning device

• US 3,939,476 A
• Filed: 05/19/1959
• Issued: 02/17/1976
• Est. Priority Date: 05/19/1959
• Status: Expired due to Term

• Current Assignee: George W. Leopard, Kirby Hair
• Original Assignee: George W. Leopard, Kirby Hair
• Inventors: Leopard, George W., Hair, Kirby
• Primary Examiner(s): Wilbur, Maynard R.
• Assistant Examiner(s): Berger, Richard E.
• Application Number:
  US03/814,353
• Time in Patent Office: 6,118 Days
• Field of Search: 343/12, 343/112.4, 343/112 D
• US Class Current: 342/464
• CPC Class Codes: G01S 11/04 using angle measurements

Abstract

1. A system for passively measuring the range between a given point and a second point from which detectable radiations having distinguishable characteristics are emanating, comprising means for receiving at said given point direct radiations from said second point and indirect radiations from said second point which have been reflected from a reflecting surface, means for measuring the angle of elevation of said second point from said given point, means for measuring the altitude of said given point relative to said reflecting surface, a gate circuit for rejecting all direct signals which are not followed by a reflecting signal within a predetermined time span, and computing means for determining the range from said given point to said second point as a function of said direct and reflected signal, said angle of elevation, and said altitude of said given point.

Claims

1. A system for passively measuring the range between a given point and a second point from which detectable radiations having distinguishable characteristics are emanating, comprising means for receiving at said given point direct radiations from said second point and indirect radiations from said second point which have been reflected from a reflecting surface, means for measuring the angle of elevation of said second point from said given point, means for measuring the altitude of said given point relative to said reflecting surface, a gate circuit for rejecting all direct signals which are not followed by a reflecting signal within a predetermined time span, and computing means for determining the range from said given point to said second point as a function of said direct and reflected signal, said angle of elevation, and said altitude of said given point.

2. A system for measuring the range between a given point and a second point from which detectable radiations having distinguishable characteristics are emanating, said system comprising means for receiving at said given point direct radiations from said second point and indirect radiations from said second point which have been reflected from a reflecting surface, means for measuring the angle of elevation of said second point from said given point, means for measuring the altitude of said given point relative to said reflecting surface, means for splitting the received signals into two paths, a delay line located in one of the paths, gate and triggering generators located in the other path, and time delay indicator means connected between the two paths responsive to said direct and reflected radiations for indicating the range between said given point and said second point.

3. The system of claim 2 wherein said time delay indicator means is a cathode ray oscilloscope whose sweep is calibrated directly in microseconds.

4. A system for measuring the range between a first aircraft and a second aircraft from which detectable radiations having distinguishable characteristics are emanating, comprising means for receiving at said first aircraft direct radiations from said second aircraft and indirect radiations from said second aircraft which have been reflected from a reflecting surface, means for measuring the angle of elevation of said second aircraft from said first aircraft, an altimeter, a gate circuit for rejecting all signals not followed within a predetermined interval by another signal, a ranging circuit combining the output of the altimeter and the gate circuits for providing an output signal proportional to the range between said first and second aircraft, and alarm means responsive to said ranging circuit output for warning the pilot of said first aircraft when the range between the two aircraft closes to a predetermined value.

5. A system for passively measuring the range between a given point and a second point from which detectable radiations having distinguishable characteristics are emanating, comprising means for receiving at said given point direct radiations from said second point and indirect radiations from said second point which have been reflected from a reflecting surface, means for measuring the altitude of said given point relative to said reflecting surface, means for measuring the angle of elevation between the second point and the given point, a gate circuit for rejecting all signals not followed within a predetermined interval by another signal, and a ranging circuit combining the outputs of the altitude measuring means and the gate circuit for providing an output voltage proportional to the range from said given point to said second point in response to said direct and reflected signals and said altitude of said given point.