GPS attitude determination system and method using optimal...

Data processing: vehicles – navigation – and relative location – Navigation – Employing position determining equipment

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C342S357490

Reexamination Certificate

active

06256583

ABSTRACT:

FIELD OF THE INVENTION
The article by Eric Sutton entitled “Optimal Search Space Identification for Instantaneous Integer Cycle Ambiguity Resolution,” presented at the ION-GPS-97 Conference on Sep. 17, 1997, is herein incorporated by reference.
The present invention relates to global positioning system (GPS) attitude determining apparatus, systems and methods. More particularly, the present invention relates to instantaneous integer cycle ambiguity resolution methods, and systems and apparatus using the same.
BACKGROUND OF THE INVENTION
GPS attitude determination systems use GPS phase measurements to determine the orientation of a baseline defined by two antennas. Because antenna separation is generally greater than one wavelength, there is an integer ambiguity for each satellite that must be determined before the orientation of the baseline can be calculated. Since for attitude determination the baseline length is precisely known, the initial integer ambiguity search seeks to identify all solutions that result in a baseline length close to the true baseline length.
Integer cycle ambiguity resolution is a problem commonly encountered in GPS applications such as attitude determination and kinematic positioning. There are many recent papers on the design and performance of ambiguity resolution algorithms for kinematic positioning. Ambiguity resolution for attitude determination is different from ambiguity resolution for kinematic positioning in that for attitude determination the baseline is generally relatively short and the baseline length is very precisely known. Therefore, for attitude determination systems, the initial integer cycle ambiguity search is generally performed in solution space instead of measurement space. In other words, the initial search is based on baseline length instead of on the phase residual.
It has been shown in several recent papers that instantaneous ambiguity resolution is often possible for attitude determination systems. There are two principal design issues for ambiguity resolution: (1) Determination of the smallest possible search space from all available information and design requirements; and (2) Efficient identification of all solutions that lie in the search space. Due to the fundamental structure of the problem, an instantaneous ambiguity resolution algorithm cannot guarantee that it will produce exactly one solution, and even when exactly one solution is produced, it cannot guarantee that the solution is correct.
SUMMARY OF THE INVENTION
Disclosed are an integer cycle ambiguity resolution method, and attitude determining systems and apparatus using the same. In the method of determining a solution to an integer cycle ambiguity, four primary satellites out of a GPS satellite constellation are selected such that a number of false solutions for the integer cycle ambiguity is optimized. Next, a search space is defined such that the probability of rejecting a correct solution for the integer cycle ambiguity is guaranteed to be below a predetermined value. Next, intervals in the defined search space are searched to determine a solution to the integer cycle ambiguity. Then, attitude is determined as a function of the determined solution to the integer cycle ambiguity.


REFERENCES:
patent: 5602741 (1997-02-01), Talbot et al.
patent: 5610614 (1997-03-01), Talbot et al.
patent: 5825326 (1998-10-01), Semler et al.
patent: 5903236 (1999-05-01), Lawrence
patent: 5917448 (1999-06-01), Mickelson
patent: 5935194 (1999-08-01), Talbot et al.
patent: 6005514 (1999-12-01), Lightsey
patent: 6052647 (2000-04-01), Parkinson et al.
Eric Sutton, “Optimal Search Space Identification for Instantaneous Integer Cycle Ambiguity Resolution”, ION-GPS-97 Conference, Sep. 17, 1997.
Brown, R., “Instantaneous GPS Attitude Determination,” Proc. of IEEE Position Location and Navigation Symposium (PLANS '92), pp. 113-120, Monterey, California, Mar. 1992.
Euler, H.J. and C.D. Hill, “Attitude Determination Exploiting All Information for Optimal Ambiguity Resolution,” Proc. of ION-GPS-95, pp. 1751-1757, Palm Springs California, 1995.
Hatch, R., “Ambiguity Resolution in the Fast Lane,” Proc. of ION-GPS-89, pp. 45-50, Colorado Springs, Colorado, 1989.
Hill, C.D. and H.-J. Euler, “An Optimal Ambiguity Resolution Technique for Attitude Determination,” Proc. of IEEE Position Location and Navigation Symposium (PLANS '96), pp. 262-269, Atlanta Georgia, Apr. 22-26, 1996.
Knight, D., “A New Method of Instantaneous Ambiguity Resolution,” ION-GPS-94, pp. 707-716, Salt Lake City, Utah, Sep. 20-23, 1994.
Macabiau, C. and A. Benhallam, “Analysis of the Error Probability and Stopping Time of the MAPAS Procedure,” Proc. of ION-GPS-96, pp. 925-934, Kansas City, Missouri, Sep. 17-20, 1996.
Quinn, P.G., “Instantaneous GPS Attitude Determination,” Proc. of ION-GPS-93, pp. 603-615, Salt Lake City, Utah, Sep. 22-24, 1993.
Teunissen, P.J.G., P.J. de Jonge and C.C.J.M. Tiberius, “On the Spectrum of the GPS DD-ambiguities,” Proc. of ION-GPS-94, pp. 115-124, Salt Lake City, Utah, Sep. 20-23, 1994.
Teunissen, P.J.G., P.J. de Jonge and C.C.J.M. Tiberius, “The Volume of the GPS Ambiguity Search Space and its Relevance for Integer Ambiguity Resolution,” Proc. of ION-GPS-96, pp. 889-898, Kansas City, Missouri, Sep. 17-20, 1996.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

GPS attitude determination system and method using optimal... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with GPS attitude determination system and method using optimal..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and GPS attitude determination system and method using optimal... will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-2560861

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.