Apparatus and method for locating missing persons, animals, and objects

Claims

What is claimed is:

1. A method for locating a missing person, animal, or object, said method comprising the steps of:

(a) providing a transponder having an access code that identifies said transponder, said transponder configured to receive an interrogation radio signal and transmit a response radio signal, said transponder transmitting said response radio signal in response to receiving said interrogation radio signal if said interrogation radio signal includes a code matching said access code;

(b) determining said access code corresponding to said transponder;

(c) transmitting said interrogation radio signal including said access code from a transmitter located aboard an Earth-orbiting satellite;

(d) receiving said response radio signal;

(e) measuring a Doppler shift in frequency of said response radio signal; and

(f) calculating a position of said transponder based on said Doppler shift.

2. The method of claim 1, further comprising the step of repeating steps (c) through (f) to determine the rate of change of said Doppler shift in frequency in said response radio signal.

3. The method of claim 2, further comprising the step of repeating steps (c) through (f) from satellites in a low to medium Earth orbiting constellation.

4. The method of claim 1, wherein said interrogation radio signal is limited to a known position above the surface of the Earth.

5. The method of claim 1, wherein said response radio signal includes a status code.

6. The method of claim 1, wherein further comprising the steps of sending an access code to said satellite and receiving said position from said satellite.

7. A transponder adapted for connection to a hand-held device, said transponder comprising:

means for storing an identification access code;

means for receiving an interrogation radio signal; and

means for transmitting a response radio signal to an Earth-orbiting satellite, said transponder transmitting said response radio signal in response to receiving said interrogation radio signal if said radio signal includes a code matching said access code.

8. The transponder of claim 7, further comprising means for connecting said transponder to a battery to power said hand-held device.

9. The transponder of claim 7, wherein said transponder is integral to said battery.

10. The transponder of claim 6, further comprising means for inputting a status code specifying the nature of an emergency and means for incorporating said status code into said response radio signal.

11. A monitoring station comprising:

a database for storing data regarding a plurality of transponders; and

a first communication system configured to communicate with one or more Earth-orbiting satellites, said satellites configured to send interrogation signals to a transponder, said transponder configured to receive and reply to said interrogation signals;

a second communication system, said communication system configured to provide a client with data regarding a location of said transponder; and

a data processing system, said data processing system configured to:

determine said location of said transponder on an event basis;

determine said location of said transponder on a monitored basis; and

respond to status information embedded in said response signal.

12. The monitoring station of claim 11, wherein said interrogation signals and said response signals are encrypted.

13. The monitoring station of claim 12, further comprising a display for displaying said location of said transponder.

14. The monitoring station of claim 11, wherein said data processing system is further configured to produce billing information.

15. The monitoring station of claim 11, wherein said status information signal comprises biometric data about an individual, said data processing system further configured to identify anomalies in said biometric data.

16. The monitoring station of claim 11, wherein said monitoring station further includes a data archival storage system for storing information from said transponder.

17. The monitoring station of claim 16, wherein said archival data storage system instructs said second communication system to send a message to said client upon the occurrence of a predetermined selective event as determined by said client.

18. The monitoring station of claim 11, wherein said monitoring station comprises a display configured to show data from said transponder, said display configured to show alphanumeric characters and graphical maps.

19. The monitoring station of claim 18 wherein said display comprises a multi-color, graphical map display showing a global view of movement of said transponder over an extended period of time.

20. The monitoring station of claim 11, wherein said data processing system is further configured to generate a warning announcement when said transponder is outside a prescribed area.

21. A method of remotely and interactively communication with an monitoring the location of a transponder comprising the steps of:

establishing a monitoring station for maintaining location, and other data with respect to said transponder; and

transmitting location and condition information from said transponder to said monitoring station by inputting information to a transponder worn by said individual, transmitting said information by said transponder to a satellite, and relaying said information by said satellite to said monitoring station;

broadcasting interrogations by said monitoring station for receipt and relay by said satellite to said transponder, said transponder alerting said individual to the receipt of said interrogations;

providing at least one microcontroller in said transponder which supports a continuous monitoring of interrogations, alarm conditions, and data from a micro electromechanical sensor; and

providing at least one microprocessor in said transponder which supports accumulating said data for transmission and sending said data as a single compressed data packet to said monitoring station.

22. A system for locating and monitoring an individual comprising:

a monitoring station for maintaining location information and other data regarding said individual; and

a transponder worn by said individual in a manner for conveniently receiving medical and other information inputted directly from said individual, said transponder configured to communicate with a satellite for transmitting said information to said monitoring station, said satellite configured to collect data used to determine the location of said transponder, said transponder including vibratory annunciator means for alerting said individual to receipt of a signal from said monitoring station, said transponder worn by said individual in a manner to permit convenient access to input and receive information, said transponder further comprising buttons for initiating transmittal of emergency conditions representing different types o