Electronic tracking and ranging system

• US 7,389,180 B2
• Filed: 02/06/2004
• Issued: 06/17/2008
• Est. Priority Date: 02/06/2004
• Status: Expired due to Fees

• Current Assignee: Kent Pearce, Teryl Pratt
• Original Assignee: Kent Pearce, Teryl Pratt
• Inventors: Pratt, Teryl, Pearce, Kent
• Primary Examiner(s): Camby; Richard M.
• Application Number:
  US10/773,700
• Publication Number:
  US 20050177306A1
• Time in Patent Office: 1,593 Days
• Field of Search: 701/207, 375/140, 375/146, 375/147, 375/226, 375/371, 375/376, 340/573.1, 340/573.4, 340/539.13, 340/539.15, 340/825.49
• US Class Current: 701/207
• CPC Class Codes: G01S 13/84 for distance determination by phase measurement

Abstract

An electronic tracked and ranging system is disclosed. Electronic tracking and ranging system applies interferometer principles to determine ranging distance from a monitor unit 10 to a tracked unit 12. In particular, the system transmits a monitor direct sequence spread spectrum (MDSSS) 52 signal from a monitor unit 10 to a tracked unit 12. Afterwards, tracked unit 12 transmits a tracked direct sequence spread spectrum (TDSSS) 56 signal. Finally, monitor unit 10 receives TDSSS 56, performs a comparison to a reference MDSSS signal 52 locks between MDSSS signal 52 and TDSSS signal 56 and outputs distance between monitor unit 10 and tracked unit 12 using several phase comparisons. Multiple frequencies within MDSSS signal 52 are phase detected so as to increase accuracy of monitor unit 10 ranging distance to tracked unit 12.

Claims

1. An electronic system for locating an object comprising:

a monitor unit having a micro-controller, wherein the monitor unit transmits a monitor direct sequence spread spectrum (MDSSS) signal having a pseudo-random noise sequence, a monitor first frequency component and a monitor second frequency component;

a tracked unit placed on the object and receiving the MDSSS signal from the monitor unit and transmits a tracked direct sequence spread spectrum (TDSSS) signal having a pseudo-random noise sequence, a first frequency component and a second frequency component to the monitor unit; and

wherein the micro-controller compares the first frequency component of the TDSSS signal to the monitor first frequency component of the MDSSS signal creating a first phase difference utilized for a coarse accuracy determination of the distance relative between the monitor unit and the tracked unit,

further wherein the micro-controller compares the second frequency component of the TDSSS signal to the monitor second frequency component of the MDSSS signal to create a second phase difference utilized for a medium accuracy determination of range between the tracked unit on the object and the monitor unit.

2. The electronic system as recited in claim 1, wherein the monitor unit further includes a monitor phase detector, the MDSSS signal further includes a monitor third frequency component and the TDSSS signal further includes a third frequency component, wherein the monitor phase detector compares the third frequency component of the TDSSS signal with the monitor third frequency component to create a third phase difference;

and the micro-controller determines the number of repeated frequency cycles of the third frequency component of the TDSSS signal to the monitor third frequency component of the MDSSS signal for fine accuracy determination of range between the tracked unit on the object and the monitor unit.

3. The electronic system as recited in claim 1, wherein the first frequency component of the TDSSS signal is a repetition rate of the TDSSS pseudo-random noise sequence and the monitor first frequency component is a repetition rate of the MDSSS pseudo-random noise sequence.

4. The electronic system as recited in claim 1, wherein the second frequency component of the TDSSS signal is a chipping frequency of the TDSSS pseudo-random sequence and the monitor second frequency component of the MDSSS is a chipping frequency of the MDSSS pseudo-random noise sequence.

5. The electronic system as recited in claim 2, wherein the third frequency component of the TDSSS signal is a carrier frequency and the monitor third frequency component of the MDSSS signal is a carrier frequency.

6. The electronic system as recited in claim 1, wherein the monitor unit further includes a first monitor antenna disposed on the monitor unit and a second monitor antenna disposed on the monitor unit, wherein the first monitor antenna is cross-polarized relative to the second monitor antenna for measuring the object distance and relative angle from the monitor unit.

7. The electronic system as recited in claim 1, wherein the second frequency component of the TDSSS signal is a pseudo-random noise sequence input into a first shift register and a second shift register, creating the first phase difference between the second frequency component of TDSSS signal and the monitor second frequency component of the MDSSS signal.

8. The electronic system as recited in claim 1, wherein the tracked unit further includes a tracked modulator and a tracked phase detector, wherein the tracked modulator shifts the TDSSS pseudo-random noise sequence and inputs the shifted TDSSS pseudo-random noise sequence into the tracked phase detector until the TDSSS pseudo-random noise sequence locks with the MDSSS pseudo-random noise sequence.

9. The electronic system as recited in claim 1, wherein the monitor unit includes a monitor compass having concentric rings wherein the monitor micro-controller is in electrical communication with the monitor compass, which displays location of the tracked unit within the concentric rings to provide a visual display for a user of the ranging distance between the monitor unit and the tracked unit, when in use.

10. The electronic system as recited in claim 1, wherein the monitor unit further comprises a monitor compass having user selectable zones represented by concentric zone rings, wherein the monitor compass displays the distance of the tracked unit relative to the monitor unit within the user selectable zones.

11. An electronic system for locating an object comprising:

a monitor unit having a micro-controller having a monitor phase detector, wherein the monitor unit transmits a monitor direct sequence spread spectrum (MDSSS) signal having a pseudo-random noise sequence, a monitor first frequency component and a monitor second frequency component;

a tracked unit placed on the object receiving the MDSSS signal from the monitor unit and transmits a tracked direct sequence spread spectrum (TDSSS) signal having a first frequency component, a second frequency component and a pseudo-random noise sequence, to the monitor unit;

wherein the micro-controller compares the first frequency component of the TDSSS signal to the monitor first frequency component of the MDSSS signal creating a first phase difference utilized for a coarse accuracy determination of the object distance ranging relative to the monitor unit;

further wherein, the micro-controller compares the second frequency component of the TDSSS signal with the monitor second frequency component of the MDSSS signal to create a second phase difference; and

wherein the monitor phase detector monitors phase error output to determine number of repeated frequency periods of the second frequency component of the TDSSS signal for a medium accuracy determination of range relative to the monitor unit of the object range,

wherein the first frequency component of the TDSSS signal is a repetition rate of the TDSSS pseudo-random noise sequence and

wherein the second frequency component of the TDSSS signal is a chipping frequency of the TDSSS pseudo-random noise sequence.

12. The electronic system as recited in claim 11, wherein the tracked unit further includes a tracked phase detector, the TDSSS signal further includes a third frequency component and the MDSSS signal further includes a monitor third frequency component, wherein the tracked phase detector compares the third frequency component of the TDSSS signal with the monitor third frequency component of the MDSSS to create a third phase difference;

and

wherein the micro-controller determines the number of repeated frequency cycles of the third frequency component of the TDSSS signal for fine accuracy determination of distance between the monitor and tracked unit.

13. The electronic system as recited in claim 12, wherein the third frequency component of the TDSSS signal is a carrier frequency and the monitor third frequency component of the MDSSS signal is a carrier frequency.

14. The electronic system as recited in claim 11, wherein the monitor unit further comprises a first monitor antenna disposed on the monitor unit and a second monitor antenna disposed on the monitor unit, wherein the first monitor antenna is cross-polarized relative to the second monitor antenna for measuring the object range and relative angle from the monitor unit.

15. The electronic system as recited in claim 11, wherein the monitor unit further includes a first shift register and second shift register and the second frequency component of the TDSSS signal is input into the first shift register and the second shift register, creating the first phase difference between the second frequency component of the TDSSS signal and the second frequency component of the MDSS signal.

16. The electronic system as recited in claim 11, wherein the monitor unit further comprises a monitor compass having at least four coverage zones indicated by concentric rings, which displays object ranging distance between the tracked unit and the monitor unit, wherein a user selects one coverage zone from the concentric rings for tracking the tracked unit.

17. A method for detecting the range of an object comprising:

placing a tracked unit on the object, wherein the track unit includes a tracked direct spread spectrum (TDSSS) signal having a first frequency component and a second frequency component;

transmitting from a monitor unit a monitor direct sequence spread spectrum (MDSSS) signal having a monitor first frequency component and a monitor second frequency component, wherein the monitor unit includes a monitor phase detector;

receiving the MDSSS signal at the tracked unit;

transmitting from the tracked unit the TDSSS signal to the monitoring monitor unit;

comparing the first frequency component of the TDSSS signal to the monitor first frequency component of the MDSSS signal within the monitor-phase detector;

outputting a first phase shift for course accuracy determination of the object range relative to the monitor unit;

comparing the second frequency of the TDSSS signal to the monitor second frequency component of the MDSSS signal within the monitor phase detector,

outputting a second phase-shift; and

,

determining the number of repeated frequency periods of the second frequency component of the TDSSS signal.