Global Positioning System (GPS) and Doppler Augmentation (GDAUG) and Space Location Inertial Navigation Geopositioning System (SPACELINGS)

• US 20130293414A1
• Filed: 05/03/2012
• Published: 11/07/2013
• Est. Priority Date: 05/03/2012
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Robinson, Ian S., Skidmore, Mark
• Granted Patent: US 9,019,155 B2
• Time in Patent Office: Days
• US Class Current: 342/357.25
• CPC Class Codes: G01S 1/02 using radio waves G01S19/00 takes precedence
• CPC Class Codes: G01S 13/74 Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems
• CPC Class Codes: G01S 19/05 providing aiding data
• CPC Class Codes: G01S 19/08 providing integrity information, e.g. health of satellites or quality of ephemeris data
• CPC Class Codes: G01S 19/11 wherein the cooperating elements are pseudolites or satellite radio beacon positioning system signal repeaters
• CPC Class Codes: G01S 19/42 Determining position
• CPC Class Codes: G01S 5/0226 Transmitters

Abstract

A global positioning system (GPS) and Doppler augmentation (GDAUG) end receiver (GDER) can include a GDAUG module. The GDAUG module can generate a GDER position using a time of flight (TOF) of a transponded GPS signal and a Doppler shift in a GDAUG satellite (GSAT) signal. The transponded GPS signal sent from a GSAT to the GDER can include a frequency shifted copy of a GPS signal from a GPS satellite to the GSAT. The GSAT signal can include a signal generated by the GSAT to the GDER.

Claims

1. A global positioning system (GPS) and Doppler augmentation (GDAUG) end receiver (GDER), comprising:

a GDAUG module, wherein the GDAUG module generates a GDER position using a time of flight (TOF) of a transponded GPS signal and a Doppler shift in a GDAUG satellite (GSAT) signal, and wherein the transponded GPS signal sent from a GSAT to the GDER comprises a frequency shifted copy of a GPS signal from a GPS satellite to the GSAT, and the GSAT signal comprises a signal generated by the GSAT to the GDER.

2. The GDER of claim 1, wherein the GDAUG module further comprises:

a Doppler shift module that measures a Doppler shift in the GSAT signal;

a GSAT ephemeris estimator that determines a GSAT position by measuring a trend in a plurality of GSAT Doppler shift measurements from a plurality of GSAT signals;

a range estimator that calculates a GSAT range from the GSAT position and a super-range measurement of the transponded GPS signal, wherein the super-range measurement represents a distance from the GPS to the GDER via the GSAT; and

a receiver location estimator that estimates a GDER position using the GSAT position and the GSAT range.

3. The GDER of claim 2, wherein the Doppler shift module measures a Doppler shift in the transponded GPS signal, and the GSAT ephemeris estimator determines the GSAT position by extracting the Doppler shift due to the GSAT range from the Doppler shift of the transponded GPS signal to generate a Doppler shift of the GPS signal and by estimating the GSAT position using the Doppler shift of the GPS signal.

4. The GDER of claim 2, wherein the receiver location estimator trends a Doppler shift in a plurality of transponded GPS signals to generate a GDER position or a GDER velocity.

5. The GDER of claim 2, wherein the receiver location estimator further comprises an altimeter for determining an altitude of the GDER.

6. The GDER of claim 2, wherein the receiver location estimator further comprises at least one of a pedometer and an inertial measurement unit (IMU) for determining movement of the GDER.

7. The GDER of claim 1, wherein the GDAUG module is further configured to decode the transponded GPS signal to generate a super-range measurement, wherein the super-range measurement represents a distance from the GPS to the GDER via the GSAT.

8. The GDER of claim 1, wherein the GDAUG module is further configured for resetting the clock bias using a plurality of transponded GPS signals.

9. The GDER of claim 1, further comprising:

a GDAUG signal receiver for receiving the plurality of transponded GPS signals and the GSAT signal;

a signal despreader for demodulating the plurality of transponded GPS signals and detecting the GSAT signal.

10. The GDER of claim 9, wherein the signal despreader is further configured for extracting at least one of the time at a GPS satellite, a GPS satellite location, a GPS satellite identifier, and a GPS satellite ephemeris.

11. The GDER of claim 1, further comprising:

a GPS receiver for receiving a GPS signal directly from a GPS satellite and for determining a global position using a plurality of GPS signals.

12. A method for global positioning using a global positioning system (GPS) and Doppler augmentation (GDAUG) end receiver (GDER), comprising:

generating a GDER position using a time of flight (TOF) of a transponded GPS signal and a Doppler shift in a GDAUG satellite (GSAT) signal, wherein the transponded GPS signal sent from a GSAT to the GDER comprises a frequency shifted copy of a GPS signal from a GPS satellite to the GSAT, and the GSAT signal comprises a signal generated by the GSAT to the GDER.

13. The method of claim 12, wherein generating the GDER position further comprises:

generating a super-range measurement from the transponded GPS signal, wherein the super-range measurement represents a distance from the GPS to the GDER via the GSAT;

measuring a Doppler shift in the GSAT signal;

determining a GSAT position by measuring a trend in a plurality of GSAT Doppler shift measurements from a plurality of GSAT signals;

calculating a GSAT range from the GSAT position and the super-range measurement of the transponded GPS signal; and

estimating a GDER position using the GSAT position and the GSAT range.

14. The method of claim 13, wherein determining the GSAT position further comprises measuring a Doppler shift in the transponded GPS signal, extracting the Doppler shift due to the GSAT range from the Doppler shift of the transponded GPS signal to generate a Doppler shift of the GPS signal, and estimating the GSAT position using the Doppler shift of the GPS signal.

15. The method of claim 13, wherein estimating the GDER position further comprises trending a Doppler shift in a plurality of transponded GPS signals to generate a GDER position or a GDER velocity.

16. A computer program product, comprising a non-transitory computer readable storage medium having a computer readable program code embodied therein, the computer readable program code adapted to be executed to implement the method of claim 12.

17. A global positioning system (GPS) and Doppler augmentation (GDAUG) satellite (GSAT), comprising:

a GPS signal receiver for receiving a GPS signal;

a frequency shifter for generating a transponded GPS signal from the GPS signal using a GSAT frequency band substantially different from a GPS signal frequency band;

a signal generator for generating a GSAT signal; and

a signal transmitter for transmitting the transponded GPS signal and the GSAT signal to a GDAUG end receiver (GDER).

18. The GSAT of claim 17, further comprising:

an amplifier for amplifying the received GPS signal, the transponded GPS signal, the GSAT signal, or combinations thereof.

19. The GSAT of claim 17, wherein the transponded GPS signal and a GSAT signal operate in a frequency band between a very high frequency (VHF) band to a K-under (K_u) band.

20. The GSAT of claim 17, wherein the GSAT is selected from the group consisting of a CUBESAT, a low Earth orbit (LEO) satellite, and combinations thereof, wherein the CUBESAT weighs less than 5 kilograms.