Limitations of Pseudolite Systems Using Off-The-Shelf GPS Receivers

Mustafa Ozgur Kanli

School of Surveying and Spatial Information Systems, The University of New South Wales, Sydney, Australia.

DOI:                 

Abstract

Pseudolites (PLs) are ground-based transmitters that transmit GPS-like signals. They have been used to test GPS system elements and to enhance GPS in certain applications by providing better accuracy, integrity and availability through the use of PL signals in addition to the GPS signals. PLs are also a promising technology for providing positioning in indoor, high multipath environments where GPS signals are generally unavailable or severely attenuated and of questionable quality. In experiments to date, researchers have almost exclusively used PLs that transmit C/A code on L1/L2 in order to use existing off-the-shelf GPS receivers. This is because no hardware modifications to the GPS receiver are necessary and only minor changes to the receiver firmware are needed to track a PL’s signal. However, there are some fundamental issues that limit the effectiveness of a PL system using C/A code on L1/L2. These include the legality of transmitting on L1/L2, cross-correlation between PL and GPS signals, saturation of GPS receiver front-ends, and the limited multipath mitigation offered by C/A codes. When combined with other problems inherent to all PL systems such as nearfar, multipath, and synchronization, the issues in using L1/L2 C/A code PL systems further complicates the design and deployment of such systems and places limits on its operational effectiveness. This paper presents the issues which limit PL systems that use GPS hardware and explores the impact of these issues on some common PL applications.

Keywords

pseudolite, cross-correlation, jamming

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	ACA (2004): Media Release No. 73, 1 September, http://www.aca.gov.au/aca_home/media_releases/media_e nquiries/2004/04-73.htm
[2]	Barnes J.; Rizos C.; Wang J.; Small D.; Voigt G.; Gambale N. (2003): High precision indoor and outdoor positioning using LocataNet, 2003 Int. Symp. on GPS/GNSS, Tokyo, Japan, 15-18 November, 9-18
[3]	Barnes J.; Rizos C.; Kanli M.; Small D.; Voigt G.; Gambale N.; Lamance J.; Nunan T.; Reid C. (2004): Indoor industrial machine guidance using Locata: A pilot study at BlueScope Steel, Proceedings of the 60th Annual Meeting of the U.S. Inst. Of Navigation, Dayton, Ohio, 7-9 June, 533-540.
[4]	Braasch M.S. (1996): Multipath Effects, Global Positioning System: Theory and Applications I, AIAA, 547-568.
[5]	Cobb H.S. (1997): GPS pseudolites: Theory, design, and applications, PhD Dissertation, Stanford University.
[6]	Dai L.; Wang J.; Tsujii T.; Rizos C. (2001): Pseudolite Applications in Positioning and Navigation: Modelling and Geometric Analysis, Int. Symp. on Kinematic Systemsin Geodesy, Geomatics & Navigation, Banff, Canada, 5-8 June, 482-489.
[7]	Fontana R.J.; Gunderson S.J.; (2002): Ultra-WideBand Precision Asset Location System, IEEE Conference on Ultra Wideband Systems and Technologies, May 2002, Baltimore, MD.
[8]	Forssell B.; Olsen T.B. (2003): Jamming GPS: Susceptibility of Some Civil GPS Receivers, GPS World, Vol. 14, No. 1, January, 54-58.
[9]	Global Locate (2004): Global Locate: Home, http://www.globallocate.com
[10]	Irsigler M.; Eissfeller B. (2003): Comparison of Multipath Mitigation Techniques with Consideration of Future Signal Structures, Proceedings of the 16th Int. Tech. Meeting of the Satellite Division of the U.S. Inst. Of Navigation, Portland, Oregon, 9-12 September, 2584-2592.
[11]	Klein D.; Parkinson B.W. (1986): The use of pseudo-satellites for improving GPS performance, Global Positioning System (red book), Vol III, Institute of Navigation, 135-146.
[12]	Kee C.; Jun H.; Yun D. (2000): Development of Indoor Navigation System using Asynchronous Pseudolites, Proceedings of US Institute of Navigation GPS-2000, Salt Lake City, Utah, 19-22 September, 1038-1045.
[13]	Kunysz W. (2003): A Three Dimensional Choke Ring Ground Plane Antenna, Proceedings of the 16th Int. Tech. Meeting of the Satellite Division of the U.S. Inst. Of Navigation, Portland, Oregon, 9-12 September, 1883-1888.
[14]	Wang J.; Lee H.K. (2002): Impact of Pseudolite Location Errors on Positioning, Geomatics Research Australasia, 77, 81-94.
[15]	Madhani P.H.; Axelrad P. (2001): Mitigation of the Near-Far Problem by Successive Interference Cancellation, Proceedings of the 14th Int. Tech. Meeting of the Satellite Division of the U.S. Inst. of Navigation, Salt Lake City, Utah, 11-14 September, 148-154.
[16]	Misra P.; Enge P. (2001): Global Positioning System: Signals, Measurements, and Performance, Ganga-Jamuna Press, Lincoln, Massachusetts, 2001.
[17]	Novariant (2004): Novariant: Mining – Products, http://www.novariant.com/mining/products/index.cfm
[18]	Pany T.; Eissfeller B. (2004): Code and Phase Tracking of Generic PRN Signals with Sub-Nyquist Sample Rates, Journal of the Institute of Navigation, Vol. 51, No. 2, Summer 2004, 143-159.
[19]	Progri I.F.; Michalson W.R.; Cyganski D. (2004): An OFDM/FDMA Indoor Geolocation System, Journal of the Institute of Navigation, Vol. 51, No. 2, Summer 2004, 133-142.
[20]	Psiaki M.L.; Powell S.P.; Jung H.; Kintner Jr. P.M. (2003): Design and Practical Implementation of Multi- Frequency RF Front Ends Using Direct RF Sampling, Proceedings of the 16th Int. Tech. Meeting of the Satellite Division of the U.S. Inst. of Navigation, Portland, Oregon, 9-12 September, 90-102.
[21]	Rosum (2004): Rosum Corporation. Reliable Location. Inside and Out, http://www.rosum.com
[22]	Rounds S (2004a): Jamming protection of GPS receivers; PartI: Receiver Enhancements, GPS World, Vol. 15, No. 1, January.
[23]	Rounds S (2004b): Jamming protection of GPS receivers; Part II: Antenna Enhancements, GPS World, Vol. 15, No. 2, February, 38 - 45.
[24]	Siemens (2004): Methods and Apparatus for Determining a Location of a Device, United States Patent Application Publication No. US 2004/0157625 A1.
[25]	Soderholm S.; Juhola T.; Saarnimo T.; Karttunen V. (2001): Indoor Navigation Using a GPS Receiver, Proceedings of the 14th Int. Tech. Meeting of the Satellite Division of the U.S. Inst. of Navigation, Salt Lake City, Utah, 11-14 September, 1479-1486.
[26]	Soderholm S.; Jokitalo T. (2002): Synchronized Pseudolites -The Key to Indoor Navigation, Proceedings of the 16th Int. Tech. Meeting of the Satellite Division of the U.S. Inst. of Navigation, Portland, Oregon, 9-12 September, 226-230.
[27]	Soon B.H.K.; Poh E.K.; Barnes J.; Zhang J.; Lee H.K.; Lee H.K.; Rizos C. (2003): Flight test results of precision approach and landing augmented by airport pseudolites, Proceedings of the 16th Int. Tech. Meeting of the Satellite Division of the U.S. Institute of Navigation, Portland, Oregon, 9-12 September, 2318-2325.
[28]	Stolk K.; Brown A. (2003): Phase Center Calibration and Multipath Test Results of a Digital Beam-Steered Antenna Array, Proceedings of the 16th Int. Tech. Meeting of the Satellite Division of the U.S. Institute of Navigation, Portland, Oregon, 9-12 September, 1889-1897.
[29]	Van Dierendonck A.; Fenton P.; Ford T. (1992): Theory and Performance of Narrow Correlator Spacing in a GPS Receiver, Navigation, Volume 39, Number 3, 265-283.
[30]	Wang J (2002) Pseudolite Applications in Positioning and Navigation: Progress and problems, Journal of Global Positioning Systems, 1(1): 48-56.
[31]	Weiss J.P.; Anderson S.; Axelrad P. (2003): Multipath Modeling and Test Results for JPALS Ground Station Receivers, Proceedings of the 16th Int. Tech. Meeting of the Satellite Division of the U.S. Inst. of Navigation, Portland, Oregon, 9-12 September, 1801-1811.
[32]	Yun D.; Kee C. (2002): Centimeter Accuracy Stand-alone Indoor Navigation System By Synchronized Pseudolite Constellation, Proceedings of the 16th Int. Tech. Meeting of the Satellite Division of the U.S. Inst. of Navigation, Portland, Oregon, 9-12 September, 213-225.
[33]	Zimmerman K.R.; Cohen C.E.; Lawrence D.G.; Montgomery P.Y.; Cobb H.S.; Melto W.C. (2000): Multi-Frequency Pseudolites for Instantaneous Carrier Ambiguity Resolution, Proceedings of US Institute of Navigation GPS-2000, Salt Lake City, Utah, 19-22 September, 1024-1030.