Target tracking device

• US 5,023,809 A
• Filed: 06/19/1990
• Issued: 06/11/1991
• Est. Priority Date: 11/02/1987
• Status: Expired due to Fees

• Current Assignee: Precision Technology
• Original Assignee: Precision Technology
• Inventors: Whale, Henry A., Spackman, Kerry P.
• Primary Examiner(s): Lall, Parshotam S.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US07/541,089
• Time in Patent Office: 357 Days
• Field of Search: 364/516, 364/517, 364/447, 364/448, 364/449, 235/411, 358/105, 358/125, 358/126
• US Class Current: 700/90
• CPC Class Codes: G01S 5/06 Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements G01S5/12 takes precedence

Abstract

A target tracking system tracks the position of a vehicle, such as a racing vehicle. An oscillator is positioned at the target to be tracked, and a transmitter is also positioned at the target for transmitting a signal generated by the oscillator. At least three translators receive the signal transmitted from the target and each retransmits the signal to a base receiving station. The base receiving station also receives the signal sent from the target and includes a comparator for comparing each of the signals received from the translator with the signal sent directly from the target. The output of the comparator provides an indication of the position of the target relative to the base receiving station.

Claims

1. A target tracking system comprising:

an oscillator on a target;

a radio transmitter operatively connected to said oscillator whereby a radio signal representative of a signal generated by said oscillator is transmitted by said transmitter at a selected frequency;

means for translating whereby the transmitted radio signal is received and retransmitted to a base receiving station;

said base receiving station also receiving said transmitted radio signal directly from said transmitter;

said base receiving station including a reference oscillator;

processing means at said base receiving station to enable synchronicity to be maintained between said reference oscillator and the oscillator on said target;

and comparing means connected to said processing means to compare phase changes in the signal received directly from said transmitter and signals retransmitted by said means for translating with a signal generated by said reference oscillator, thereby tracking position parameters of the target relative to the means for translating and the base receiving station.

2. A method of tracking a target comprising:

generating an oscillating signal at said target;

transmitting a radio signal representative of said oscillating signal, at a selected frequency from said target;

receiving said transmitted signal at spaced apart translators;

retransmitting the receiving signal to a base receiving station from each of said spaced apart translators;

receiving said transmitted signal directly from the target at said base receiving station;

processing the signals received by the base receiving station so as to maintain synchronicity between a reference oscillator at said base receiving station and the oscillator on said target; and

comparing phase changes in the signal received directly from said target and signals retransmitted by said translators with a signal generated by said reference oscillator, thereby tracking position parameters of said target relative to said translators and said base receiving station.

3. A target tracking system comprising:

a target at which a target oscillator and a target radio transmitter are positioned, said target radio transmitter being connected to said oscillator for transmitting a radio signal at a selected frequency representative of a signal generated by said oscillator;

translating means positioned remote from said target and receiving said radio signal transmitted by said target radio transmitter and including means for retransmitting said radio signal as a retransmitted radio signal; and

a base receiving station positioned remote from said target and said translating means and receiving said radio signal transmitted by said target radio transmitter and said retransmitted radio signal and at which a reference oscillator for generating a reference signal, processing means, and comparing means are provided, said processing means enabling synchronicity between a signal generated by said reference oscillator with said signal received from said target radio transmitter, said comparing means being connected to said processing means for comparing phase changes in the radio signal transmitted by and received directly from said target radio transmitter and said retransmitted radio signal from said translating means with said reference signal generated by said reference oscillator for tracking position parameters of the target relative to said translating means and said base receiving station.

4. The target tracking system of claim 3, wherein said translating means comprises a plurality of translators each of which is positioned remote from said target and said base receiving station, each of said translators receiving said radio signal transmitted by said target transmitter and retransmitting a corresponding retransmitted radio signal for reception by said base receiving station, said comparing means of said base receiving station comparing phase changes in said radio signal received from said target radio transmitter and each of said corresponding retransmitted radio signals with said reference signal generated by said reference oscillator.

5. The target tracking system of claim 3, wherein said target is a moving target within a defined area and said position parameters of said target include position, velocity and acceleration of the target within said defined area.

6. A method for tracking a target comprising the steps of:

providing a target movable within a defined area;

generating an oscillating signal at said target;

transmitting a radio signal representative of said oscillating signal at a selected frequency from said target;

providing a plurality of translators remote from said target for receiving said radio signal and retransmitting a corresponding retransmitted radio signal;

providing a base station remote from said target;

receiving at said base station said radio signal transmitted from said target and said corresponding retransmitted radio signals from said translators;

generating a reference oscillator signal at said base station;

processing the radio signal received from said target so as to maintain synchronicity between the oscillator signal generated at said target and said reference oscillating signal at said base station; and

comparing phase changes in the radio signal received directly from said target and said corresponding retransmitted radio signals with said reference oscillator signal for tracking position parameters of said target relative to said translator and said base receiving station.

7. The method of claim 6, wherein said position parameters include position, velocity and acceleration of said target in said defined area.