Imminent collision detection apparatus

• US 4,072,944 A
• Filed: 02/20/1969
• Issued: 02/07/1978
• Est. Priority Date: 03/29/1967
• Status: Expired due to Term

• Current Assignee: Sanders Associates, INC. (BAE Systems Plc)
• Original Assignee: Sanders Associates, INC. (BAE Systems Plc)
• Inventors: Senio, Nicholas, Strang, Donald B., Bianco, Joseph F., Hawes, Russell B.
• Primary Examiner(s): Hubler, Malcolm F.
• Application Number:
  US04/808,034
• Time in Patent Office: 3,274 Days
• Field of Search: 102/70.2 P, 343/5 PD, 343/7 PF, 343/18 E, 343/7.7, 343/17.1
• US Class Current: 342/16
• CPC Class Codes: G01S 13/933 of aircraft or spacecraft

Abstract

Apparatus is herein disclosed for imminent collision detection equipment for acknowledging proximity between a first object carrying the equipment and a second object. The imminent collision detection apparatus is a radio distance measuring device and includes a transmitter and a receiver. The transmitter has a pulsed energy output which is reflected back by a target and mixed with a reference source of pulsed energy generated a predetermined time after the transmitted output and coherent thereto. The coherent feature of the equipment lies in the fact that the transmitter pulsed output and the pulsed reference signals are both generated with the same starting phase each generated pulse. Furthermore, the transmitted and reference signals are jittered to provide a resistance to countermeasures capability.

Claims

1. Apparatus for detecting imminent collision between a first object carrying said apparatus and a second object, comprising:

means for transmitting a pulsed energy signal including a first pulsed oscillator which generates signals with the same starting phase each generated pulse;

means for receiving a reflected signal from said transmitted signal;

means for generating a pulsed energy reference signal coherent to said transmitted signal including a second pulsed oscillator which generates signals with the same starting phase as said first pulsed oscillator; and

means for mixing said reflected and reference signals for producing a signal indicative of imminent collision.

2. Apparatus as defined in claim 1, further including means for generating said transmitted and reference pulses at a random pulse repetition frequency, thus precluding effective countermeasures.

3. Apparatus as defined in claim 1, further including means for generating said reference signal a predetermined time after said transmitted signal for providing a predetermined maximum proximity within which imminent collision will be indicated.

4. Apparatus as defined in claim 1, in which said means for transmitting a pulsed energy signal includes:

a noise generator;

a clock generator coupled to said noise generator; and

a pulse generator coupled to said clock generator, said first pulsed oscillator being coupled to said pulse generator.

5. Apparatus as defined in claim 4, in which said second pulsed oscillator is coupled to said pulse generator.

6. Apparatus as defined in claim 5, further including a delay network coupled between said pulse generator and said second pulsed oscillator.

7. Apparatus as defined in claim 1, further including a filter network coupled to said mixing means.

8. Apparatus as defined in claim 7, further including an alarm circuit coupled to said filter network.

9. Apparatus as defined in claim 7, further including a detonator coupled to said filter network.

10. Apparatus as defined in claim 1, in which said means for transmitting a pulsed energy signal includes means for modulating a carrier with a pulsed oscillation.

11. A method for detecting imminent collision of a first object with a second object, comprising the steps of:

transmitting a pulsed energy signal having a predetermined starting phase;

receiving an echo of said pulsed energy signal from said second object;

separately generating a pulsed energy reference signal coherent to said transmitted signals said reference signal having the same starting phase as said transmitted signal; and

mixing said reference and received signals for producing a doppler signal.

12. The method of claim 11, further including transmitting said transmitted signal with a smeared spectrum.