System and method for locating items and places

• US 9,389,297 B2
• Filed: 03/19/2009
• Issued: 07/12/2016
• Est. Priority Date: 03/19/2008
• Status: Active Grant

• Current Assignee: iSeeLoc, Inc.
• Original Assignee: iSeeLoc, Inc.
• Inventors: Zohar, Avi, Zohar, Sharon
• Primary Examiner(s): McGue, Frank J
• Application Number:
  US12/407,219
• Publication Number:
  US 20090251363A1
• Time in Patent Office: 2,672 Days
• Field of Search: 342/443
• US Class Current: 1/1
• CPC Class Codes: G01S 3/46 using antennas spaced apart and measuring phase or time difference between signals therefrom, i.e. path-difference systems
• CPC Class Codes: G01S 3/52 using a receiving antenna moving, or appearing to move, in a cyclic path to produce a Doppler variation of frequency of the received signal
• CPC Class Codes: G01S 3/54 the apparent movement of the antenna being produced by coupling the receiver cyclically and sequentially to each of several fixed spaced antennas
• CPC Class Codes: G01S 5/04 Position of source determined by a plurality of spaced direction-finders

Abstract

A locator includes a base unit and a handheld unit. The base unit, which is typically stationary, includes an FSK transceiver and printed circuit antennas. The handheld unit, which is typically mobile, also includes an FSK transceiver and printed circuit antennas. The handheld unit computes at least one bearing to the base unit over multiple frequencies and transmitting antennas, processes statistics of bearing results, determines a cyclic average of the bearing results, calculates an overall variance, assesses quality of a computed bearing result based on the overall variance, and upon assessing, either displays the computed bearing result or disqualifies the computed bearing. The handheld unit computes a height difference between the base unit and the handheld unit. The height difference is calculated using altimeters within the units. Alternatively, the height difference is calculated using GPS.

Claims

1. A method of using a locator, the method comprising:

a. transmitting a first set of information directly from a first unit to a second unit by using a narrow band transmission protocol;

b. receiving the first unit transmission at the second unit;

c. transmitting a second set of information from the second unit to the first unit if there is a first ID match in response to receiving the first unit transmission;

d. receiving the second unit transmission at the first unit; and

e. presenting data at the first unit to a user if there is a second ID match in response to receiving the second unit transmission, the data comprising a graphical arrow which indicates a calculated height difference between the first unit and the second unit, points toward the second unit regardless of the orientation of the first unit and is graphically filled proportionally to a received power as an indication of a distance between the first unit and the second unit.

2. The method of claim 1, wherein the second set of information is periodically transmitted.

3. The method of claim 1, wherein transmissions are FSK modulated and demodulated.

4. The method of claim 1, wherein the data further includes a bearing computed by the second unit.

5. The method of claim 4, wherein the bearing is calculated using Doppler effect based measurements.

6. The method of claim 4, wherein the bearing is a cyclic average of bearing results.

7. The method of claim 4, wherein the bearing is computed over multiple transmitted carrier frequencies and transmitting antennas.

8. The method of claim 1, wherein the calculated height difference is based on GPS.

9. The method of claim 1, wherein the calculated height difference is based on a pressure difference between the first unit and the second unit.

10. The method of claim 1, wherein the presenting includes the first unit beeping at a beep rate proportional to a received power as an indication of a distance between the first unit and the second unit.

11. The method of claim 1, wherein the presenting includes presenting different sounds for different information.

12. The method of claim 1, wherein the first unit is a handheld locator unit having a first set of planar antennas, and the second unit is the base locator unit having a second set of planar antennas.

13. A method of using a locator, the method comprising:

a. transmitting a first set of information from a first unit to a second unit by using a narrow band transmission protocol;

b. receiving the first unit transmission at the second unit;

c. transmitting a second set of information from the second unit to the first unit upon a first ID match;

d. receiving the second unit transmission at the first unit; and

e. presenting data at the first unit to a user upon a second ID match, the data comprising directional information to the second unit;

wherein the data further includes a graphical arrow which indicates a calculated height difference between the first unit and the second unit, points toward the second unit regardless of the orientation of the first unit and is graphically filled proportionally to a received power as an indication of a distance between the first unit and the second unit, and further wherein the presenting includes the first unit beeping at a pitch that changes proportionally to a received power as an indication of a distance between the first unit and the second unit.

14. A method of overcoming multipath effects, the method comprising:

a. computing at least one bearing to a first unit over multiple frequencies and transmitting antennas;

b. processing statistics of bearing results;

c. determining a cyclic average of the bearing results;

d. calculating an overall variance;

e. assessing quality of a computed bearing result based on the overall variance; and

f. upon assessing, either displaying the computed bearing result on a second unit or disqualifying the computed bearing.

15. The method of claim 14, wherein a bearing result deviating from the cyclic average by a predetermined amount is removed before determining the cyclic average.

16. The method of claim 14, wherein the first unit is a base unit and the second unit is a handheld unit, wherein the base unit and the second unit are used to locate items and places.

17. The method of claim 14, wherein each of the first unit and the second unit includes a set of planar antennas.

18. The method of claim 14, wherein each of the first unit and the second unit includes an FSK transceiver.

19. A method of using a locator, the method comprising:

a. transmitting a first set of information including a first destination address and a first source address directly from a first unit to a second unit by using a narrow band transmission protocol;

b. receiving the first unit transmission at the second unit;

c. transmitting a second set of information including a second destination address and a second source address from the second unit to the first unit if there is a first source address match in response to receiving the first unit transmission;

d. receiving the second unit transmission at the first unit;

e. presenting data at the first unit to a user if there is a second source address match in response to receiving the second unit transmission, the data comprising directional information to the second unit, the directional information a graphical arrow which indicates a calculated height difference between the first unit and the second unit, points toward the second unit regardless of the orientation of the first unit and is graphically filled proportionally to a received power independent of the orientation of the first unit as an indication of a distance between the first unit and the second unit, wherein presenting the data comprises the first unit beeping at a beep rate that changes proportionally to a received power as an indication of a distance between the first unit and the second unit; and

f. always refraining from presenting the data at the first unit to the user in response to receiving the second unit transmission if the second source address match does not occur.

20. The method of claim 19 wherein the second set of information comprises an altimeter reading and a bearing measurement sequence.

21. The method of claim 20 wherein the bearing measurement sequence is cyclic averaged to yield an accurate bearing result.

22. The method of claim 19 wherein the data is always presented at the first unit to the user if there the second source address match.