THEME 4: NEW POSITIONING TECHNOLOGIES & APPLICATIONS

Academic staff members of the School of Surveying & Spatial Information Systems, University of New South Wales, now undertake research and teaching in areas beyond just the narrow areas of "satellite navigation and positioning" of the original SNAP group of the 1990s, to also embrace what may be referred to as "earth observation" (geodesy, airborne and satellite remote sensing and imaging). To better describe the range of activities in the exciting fields of satellite and ground-based wireless positioning, our research projects are grouped into several themes. Download our SNAP Lab Research Directions document to see what we'll be researching over the next few years. The SNAP Lab has also produced a Research Brochure that explains the range of research topics being undertaken, identifying opportunities for potential graduate students as well as research collaboration with external partners. ...email us for a hardcopy, or download a PDF version.

Theme 4 deals with a range of research topics that are comparatively recent initiatives of the SNAP Lab. Common topics of research in surveying/geomatics departments at universities are high accuracy GPS/GNSS technology and applications (Theme 1), and sensor integration issues (Theme 3). SNAP has made a strategic decision to initiate research into other location determination technologies, from those based on short-range wireless communications to dedicated RF-based systems. These are able to address positioning in environments where GPS/GNSS (with or witthout inertial sensors) cannot provide the required accuracy and availability performance. For SNAP papers dealing with this topic area click here ...

The SNAP Lab:

• is one of the pioneers of university pseudolite research
• is a centre-of-excellence for the new terrestrial RF-based Locata positioning technology, with a functioning LocataNet testbed on the UNSW campus
• is a research collaborator with several Australian companies on wireless positioning, including Andrew Corporation and Seeker Wireless for mobilephone positioning, and G2 Microsystems for WiFi and RFID positioning
• is currently developing several multi-sensor navigation packages, including GNSS/INS/Locata and GNSS/WiFi/RFID/Mobilephone configurations

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In May 1999 SNAP purchased its first pseudolite (PL) - the IntegriNautics model IN200C-XL/G - and in June 2001 a second IntegriNautics IN200 was purchased. These PL purchases allowed a number of research projects to be initiated, including work on fundamental modelling as well as GPS/INS/PL integration (see Theme 3). The SNAP Lab is now a world leader in academic GPS+INS+PL, GPS+PL and PL-only positioning research, and has collaborated with the Ohio State University (OSU) (particularly with regards to GPS+INS+PL) and the University of Nottingham (UNott) (particularly with respect to its feasibility for structural deformation monitoring).

Early experiments with several ground-based pseudolites transmitting to a receiver on a tethered balloon at UNSW

IntegriNautics pseudolites used for SNAP Lab research

However, the PL research also spurred industry-driven R&D. This research was conducted in "stealth" mode, and first publications using the 'LocataLite' concept were published in mid-2003. Joel Barnes and former graduate students Mustafa Kanli and Anuj Pahwa were engaged in this project up until a few years ago. Nonie Politi joined SNAP in late-2006 to assist with Locata research. Several graduate students are also researching aspects of the Locata technology. Two ARC-funded projects are now progressing the Locata terrestrial positioning technology, in partnership with Leica Geosystems. First tests of the Locata on the UNSW campus commenced in November 2006. Collaborative research is also being conducted with colleagues from OSU and UNott.

One of the LocataLite transceivers located on the roof of the EE building at UNSW

Inside a LocataLite, showing transmitter and receiver sections For more photographs click here...

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Other location technology projects included the use of IEEE 802.11b (WLAN or "WiFi") Access Points for 2D positioning based on range trilateration, a research project of former graduate student Yufei Wang (2002-2006). This was extended to also include a "fingerprint" based 2D/3D positioning technique by former graduate student Binghao Li (2003-2006). This work is continuing under a new GPS/WiFi integration project "Integrating WiFi and GPS in a Navigation System for the Blind and Visually Impaired (BVI)". This research will be conducted using the WiFi/RFID development kit from G2 Microsystems.

Indoor WiFi positioning testbed on 4th floor of the EE building at UNSW

Outdoor WiFi positioning testbed in the CBD of Sydney

Research into non-line-of-sight (NLOS) error for terrestrial wireless-based positioning systems was pioneered by Dr. Keun Lee while a visiting fellow in the SNAP Lab (2002-2003), and the results of simulations have been published in a seminal paper (download here). Binghao Li has progressed this research as part of his PhD studies (see LI, B., 2006. Terrestrial Mobile User Positioning Using TDOA and Fingerprinting Techniques. PhD thesis, School of Surveying & Spatial Information Systems, University of New South Wales, Sydney, Australia, Digital Thesis here...). A new ARC-funded project ("Safe Location at Home & Abroad") with industry partner Seeker Wireless will integrate GPS with mobilephone positioning technology. The aiding of GPS using server-assistance data provided via mobilephone links has also been a topic of research (see Theme 1).

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Not all projects in Theme 4 are technology driven. An ARC-funded project "Audio Nomad - A Location-Based Handheld Audio Device for Sound-Art Applications" with researchers from the School of Computer Science & Eng. (UNSW) deals with 'spatialised sound' in an "augmented reality" context. A number of "soundscape" demonstrator projects will be developed based on a combination of GPS (or other location determination technology), WLAN, data servers, and mobile handheld devices such as PDAs. The first was SYREN, exhibited at the ISEA 2004 conference. "Syren for Port Jackson" was staged in March 2006 in Sydney. Later more sophisticated location technologies will be used, including the Locata Technology. The heart of the system is a new design of the authoring software.

The Audio Nomad Team with an early prototype positioning/audio device: Nigel Helyer, Daniel Woo & Chris Rizos

Screenshot of part of Sydney Harbour, showing the 'soundscape' between the Harbour Bridge and Opera House of "Syren for Port Jackson"

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The current activities and challenges in Theme 4 can be summarised as:

1. 
   

   Pseudolite studies at UNSW started in 1999 and have progressed rapidly until about 2004, when attention was mostly turned to the Locata technology. While a number of applications were studied, fundamental investigations concerning measurement modelling and the integrated processing of pseudolite data with GPS and INS data were also undertaken by Jinling Wang and Joel Barnes, with the assistance of former graduate students Liwen Dai (2000-2002), H.K. Lee (2001-2004), Steve Hewitson (2003-2006), and Jack Wang (mid-2003-2007). For a position paper on pseudolite augmentation of GPS, click here.

   
   
2. 
   

   LocataLite is an innovative new pseudolite-based transceiver positioning technology invented by the Locata Corporation (Canberra). Joel Barnes and former graduate students Mustafa Kanli and Anuj Pahwa (all now working for Locata Corporation) are progressing the research, in partnership with the Locata company. Several generations of prototypes have been developed, with the latest operating on the 2.4GHz ISM frequency band. In late 2006 a new research assistant, Nonie Politi, was employed to assist with Locata research. Today several ARC-funded projects seek to integrate Locata with GPS and INS.

   
   
   
3. Field Programmable Gate Arrays are reconfigurable computing devices which sit between HW and SW, and in fact may carry out some or all of the previously fixed (ASIC) hardware functions. In effect they are programmed to be a chip with any combination of logic components normally available in the form of dedicated Application Specific Integrated Chips (ASICs), such as for example, DSP, CPU, RAM, etc. A NICTA funded pilot project (2004.5-2005.5) has built an FPGA-based GPS receiver known as the 'NAMURU'. SNAP will use FPGAs also as a research platform for new GNSS receiver designs and as the platform for multi-sensor integration. An ARC project (2005-2007) "Designing Next Generation GNSS Receivers Using the Software Approach" supports research in this area of FGPAs.
   
   
4. WLAN (WiFi) positioning; the development of a short-range positioning system using the signals from a number of IEEE 802.11b Access Points, to support WLAN-based communications by laptop and PDA devices, is described in a paper downloadable here. The "fingerprint" technique is described in a paper downloadable here. WLAN-based positioning will be an important technology for moderate-accuracy indoor/outdoor positioning applications and will increasingly be integrated with other sensor technologies such as GNSS, RFID, UWB, etc.
   
   
5. Mobilephone positioning: SNAP Lab has conducted research into Assisted-GPS (as used within mobilephones for weak signal acquisition/tracking), as well as non-line-of-sight error. An ARC-funded project commenced in 2008 in collaboration with Seeker Wireless.
   
   
GIS/LBS demonstrators; as GNSS receivers are increasingly being integrated within consumer mobile devices such as mobilephones and PDAs, the applications for such technology are trending towards what many call 'Telematics', or Location-Based Services (LBS) (download a paper on this topic). Many of these services use location information to access spatial databases, as generally associated with Geographic Information Systems (GIS). LBS are expected to dominate the market for GNSS products and services, but all LBS can be considered variations of basic GIS-type functions such as 'where am I?', 'where are you?', 'how do I get from A to B?', 'show me a map ....', and so on. Although the SNAP Lab does not undertake fundamental research into GIS or LBS, demonstrator projects are developed that illustrate the technologies and deliverables of simple LBS using the UNSW campus as a test site. One student example is a 'micro-routing' LBS project (click here ... 1.7MB PDF).

A Short History ...

1. Integration of GPS with Unsynchronised Pseudolites: fundamental modelling research, software development and field trials was commenced by former graduate students Liwen Dai (see DAI, L., 2002, Augmentation of GPS with Glonass and Pseudolite Signals for Carrier Phase-Based Kinematic Positioning, UNISURV S-72) and H.K. Lee (see LEE, H.K., 2004, Integration of GPS/Pseudolite/INS for High Precision Kinematic Positioning and Navigation, UNISURV S-76) supported by former research associate Joel Barnes and former visiting fellow Dr. Toshiaki Tsujii. The pseudolites that were used were purchased from the IntegriNautics company, as well as specially modified signal generators from Spirent. Field trials involved kinematic and static application-type scenarios, including trials in light aircraft by former graduate students Ben Soon and Jack Wang. Sample papers (see also Theme 3):
   
   BARNES, J., WANG, J., RIZOS, C., NUNAN, T., & REID, C., 2002. The development of a GPS/pseudolite positioning system for vehicle tracking at BHP Billiton steelworks. 15th Int. Tech. Meeting of the Satellite Division of the U.S. Inst. of Navigation, Portland, Oregan, 24-27 September, 1779-1789.(Download PDF)
   KANLI, M., 2004. Limitations of pseudolite systems using off-the-shelf GPS receivers. 2004 Int. Symp. on GNSS/GPS, Sydney, Australia, 6-8 December. (Download PDF)
   LEE, H.K., WANG, J., RIZOS, C., & GREJNER-BRZEZINSKA, D., 2004. Analysing the impact of integrating pseudolite observations into a GPS/INS system. Journal of Surveying Engineering, 130(2), 95-103. (Download PDF)
   SOON, B.K.H., BARNES, J., LEE, H.K., ZHANG, J., RIZOS, C., WANG, J., & LEE, H.K., 2004. Real-time flight test results of an integrated GPS/INS/pseudolite autolanding system. GNSS2004, Rotterdam, The Netherlands, 16-19 May, CD-ROM proc., paper 16. (Download PDF)
   WANG, J., TSUJII, T., RIZOS, C., DAI, L., & MOORE, M., 2000. Integrating GPS and pseudolite signals for position and attitude determination: Theoretical analysis and experiment results. 13th Int. Tech. Meeting of the Satellite Division of the U.S. Inst. of Navigation, Salt Lake City, Utah, 19-22 September, 2252-2262. (Download PDF)
   WANG, J., RIZOS, C., DAI, L., TSUJII, T., BARNES, J., GREJNER-BRZEZINSKA, D., & TOTH, C.K., 2001. Integration of GPS and pseudo-satellites: New concepts for precise positioning. IAG Scientific Assembly, Budapest, Hungary, 2-7 September, CD-ROM proc. Symp. C3 "New Concepts in Engineering Geodesy", paper 2. (Download PDF)
   TSUJII, T., HARIGAE, M., BARNES, J., WANG, J., & RIZOS, C., 2002. A preliminary test of the pseudolite-based inverted GPS positioning in kinematic mode. 2nd Symp. on Geodesy for Geotechnical & Structural Applications, Berlin, Germany, 21-24 May, 442-451. (Download PDF)
   

2. LOCATA Technology (Initial Studies): in mid-2003 a new Australian-designed, pseudolite-based "transciever" positioning technology was announced by the Locata Corporation (Canberra). Over the next 3 years the former research associate Dr. Joel Barnes performed a series of tests, and the research was progressed with the assistance of former graduate students Mustafa Kanli and Anuj Pahwa. (All have since joined the Locata Corporation.) The results have been published in a series of papers:
   
   BARNES, J., RIZOS, C., WANG, J., SMALL, D., VOIGHT, G., & GAMBALE, N., 2003. Locatanet: The positioning technology of the future? 6th Int. Symp. on Satellite Navigation Technology Including Mobile Positioning & Location Services, Melbourne, Australia, 22-25 July, CD-ROM proc., paper 49. (Download PDF) BARNES, J., RIZOS, C., WANG, J., SMALL, D., VOIGHT, G., & GAMBALE, N., 2003. Locatanet: A new positioning technology for high precision indoor and outdoor positioning. 16th Int. Tech. Meeting of the Satellite Division of the U.S. Institute of Navigation, Portland, Oregan, 9-12 September, 1119-1128. (Download PDF) BARNES, J., RIZOS, C., WANG, J., SMALL, D., VOIGHT, 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. (Download PDF)
   BARNES, J., WANG, J., RIZOS, C., SMALL, D., VOIGHT, G., & GAMBALE, N., 2003. Guidelites: Intelligent synchronised pseudolites for cm-level stand-alone positioning. 11th Int. Assoc. of Institutes of Navigation (IAIN) World Congress, Berlin, Germany, 21-24 October, CD-ROM proc., paper 202. (Download PDF)
   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. 60th Annual Meeting of the U.S. Inst. Of Navigation, Dayton, Ohio, 7-9 June. (Download PDF)
   BARNES, J., RIZOS, C., KANLI, M., PAHWA, A., SMALL, D., VOIGT, G., GAMBALE, N., & LAMANCE, J., 2005. High accuracy positioning using Locata's next generation technology. 18th Int. Tech. Meeting of the Satellite Division of the U.S. Institute of Navigation, Long Beach, California, 13-16 September, 2049-2056. (Download PDF)
   BARNES, J., RIZOS, C., KANLI, M., & PAHWA, A., 2006. A positioning technology for classically difficult GNSS environments from Locata. IEEE/ION PLANS, San Diego, California, 25-27 April, 715-721. (Download PDF)
   BARNES, J., RIZOS, C., KANLI, M., & PAHWA, A., 2006. Locata: A new positioning technology for classically difficult GNSS environments. Symp. on GPS/GNSS (IGNSS2006), Surfers Paradise, Australia, 17-21 July, CD-ROM procs. (Download PDF)
   BARNES, J., RIZOS, C., KANLI, M., & PAHWA, A., 2006. A solution to tough GNSS land applications using terrestrial-based transceivers (LocataLites). 19th Int. Tech. Meeting of the Satellite Division of the U.S. Inst. of Navigation, Fort Worth, Texas, 26-29 September, 1487-1493. (Download PDF)

3. LOCATA Technology (Current Studies): at the end of 2006 a LocataLite network was established permanently at UNSW and a new era of Locata research commenced. New staff (Mr. Nonie Politi) and new graduate students (Manuel Abello, Faisal Khan, Mazher Choudhury, Tim Norton) were recruited. Some recent papers:
   
   ABELLO, M., DEMPSTER, A.G., & MILFORD, G., 2007.  Phase centre location determination for Locatalite and rover antenna in the Locata system.  IGNSS2007 Symp. on GPS/GNSS, Sydney, Australia, 4-6 December, paper 57, CD-ROM procs. (Download PDF)ABELLO, M., DEMPSTER, A.G., & POLITI, A., 2007.  ISM band interference and Locata.  IGNSS2007 Symp. on GPS/GNSS, Sydney, Australia, 4-6 December, paper 58, CD-ROM procs. (Download PDF)
   BARNES, J., CRANENBROECK, J.van, RIZOS, C., PAHWA, A., & POLITI, A., 2007. Long term performance analysis of a new ground-transceiver positioning network (LocataNet) for structural deformation monitoring applications.FIG Working Week "Strategic Integration of Surveying Services", Hong Kong, 13-17 May, CD-ROM procs, Session TS5A GNSS2. (Download PDF)
   
   

4. Non-Line-Of-Sight (NLOS) error: for terrestrial-based wireless positioning systems this is a constraint to increasing the accuracy of, e.g., mobilephone psoitioning techniques such as TDOA, E-OTD, etc. This research was commenced by Dr. Keun Lee while a visiting fellow at UNSW (2002-2003). Former graduate student Binghao Li (2003-2006) progressed this research in his PhD studies (see LI, B., 2006. Terrestrial Mobile User Positioning Using TDOA and Fingerprinting Techniques. PhD thesis, School of Surveying & Spatial Information Systems, University of New South Wales, Sydney, Australia, Digital Thesis here...). Papers include:
   
   LEE, H.K., & RIZOS, C., 2003. A framework for calibrating NLOS error to support LBS in urban environments. 2003 Int. Symp. on GPS/GNSS, Tokyo, Japan, 15-18 November, 69-77. (Download PDF)
   LI, B., DEMPSTER, A.G., RIZOS, C., LEE, H.K., & LI, D., 2005. Application of interpolation to mobile phone fingerprinting for positioning. 18th Int. Tech. Meeting of the Satellite Division of the U.S. Institute of Navigation, Long Beach, California, 13-16 September, 2268-2276. (Download PDF)
   LI, B., RIZOS, C., & LEE, H.K., 2004. Utilzing kriging to generate a NLOS correction map for network based mobile positioning. Int. Symp. on GNSS/GPS, Sydney Australia, 6-8 December. (Download PDF)
   LI, B., DEMPSTER, A.G., RIZOS, C., & LEE, H.K., 2006. A database method to mitigate NLOS error in mobilephone positioning. IEEE/ION PLANS, San Diego, California, 25-27 April, 173-178. (Download PDF)
   
   
5. Positioning Using WLAN ("WiFi"): the development of a short-range positioning system using the signals from a number of IEEE 802.11b Access Points, installed on the 4th floor of the Electrical Eng. Building to support WLAN-based communications by laptop and PDA devices, was an initiative of former graduate student Yufei Wang. The "fingerprint" technique was also investigated by former graduate student Binghao Li. Continuing research is supported by Faculty funding, and includes outdoor WLAN and direction-based positioning. Some papers:
   
   LI, B., DEMPSTER, A.G., RIZOS, C., & BARNES, J., 2005. Hybrid method for localization using WLAN. Spatial Sciences Conference, Melbourne, Australia, 12-16 September. (Download PDF)
   LI, B., DEMPSTER, A.G., BARNES, J., RIZOS, C., & LI, D., 2005. Probabilistic algorithm to support the fingerprinting method for CDMA location. Int. Symp. on GPS/GNSS, Hong Kong, 8-10 December, paper 9C-05, CD-ROM procs. (Download PDF)
   LI, B., KAM, J., LUI, J., DEMPSTER, A.G., & RIZOS, C., 2007.  Direction-based Wireless LAN positioning.  4th Int. Symp. on Location Based Services & TeleCartography, Hong Kong, 8-10 November, 306-316, CD-ROM procs. (Download PDF)
   LI, B., RIZOS, C., & LEE, H.K., 2005. Utilzing kriging to generate a NLOS correction map for network based mobile positioning. Journal of GPS, 4(1-2), 27-35. (Download PDF)
   LI, B., SALTER, J., DEMPSTER, A.G., & RIZOS, C., 2006. Indoor positioning techniques based on Wireless LAN. 1st IEEE Int. Conf. on Wireless Broadband & Ultra Wideband Communications, Sydney, Australia, 13-16 March, paper 113, CD-ROM procs. (Download PDF)
   LI, B., WANG, Y., LEE, H.K., DEMPSTER, A.G., & RIZOS, C., 2005. A new method for yielding a database of location fingerprints in WLAN. IEE Proc. Communications, 152(5), 580-586. (Download PDF)
   WANG, Y., JIA, X., & RIZOS, C., 2004. Two new algorithms for indoor Wireless Positioning System (WPS). 17th Int. Tech. Meeting of the Satellite Division of the U.S. Institute of Navigation, Long Beach, California, 21-24 September, 1988-1997. (Download PDF)
   WANG, Y., JIA, X., & RIZOS, C., 2004. Differential algorithms for indoor wireless positioning systems (DWPS). 2004 Int. Symp. on GNSS/GPS, Sydney, Australia, 6-8 December. (Download PDF)
   
   
6. Integrated Navigation for Indoor/Personal Navigation: research on WLAN-based positioning is continuing, supported by Faculty funding for research associate Dr. Binghao Li, but directed to its integration with GPS and other "ubiquitous positioning" technologies such as RFID, UWB and ZigBee. Some papers:
   
   LI, B., 2006. Terrestrial mobile user positioning using TDOA and fingerprinting techniques. PhD thesis, School of Surveying & Spatial Information Systems, University of New South Wales, Sydney, Australia. (Digital Thesis here...)
   
   
7. "Audio Nomad": an ARC-funded (2003.5-2006.5) project undertaken in collaboration with Dr. Daniel Woo (School of Computer Science & Eng., UNSW) and Dr. Nigel Helyer (Sonic Landscape Artist), and other Location-Based Service (LBS) studies:
   

   
   DAO, D., RIZOS, C., & WANG, J., 2002. Location-Based Services: Technical and business issues. GPS Solutions, 6(3), 169-178. (Download PDF)
   RAPER, J., GARTNER, G., KARIMI, H., & RIZOS, C., 2007. A critical evaluation of location based services and their potential. Journal of Location Based Services, 1(1), 5-46. (Download PDF)
   WOO, D., MARIETTE, N., HELYER, N., & RIZOS., C., 2005. SYREN - A ship based location-aware audio experience. Journal of GPS, 4(1-2), 41-47. (Download PDF)
   WOO, D., MARIETTE, N., SALTER, J., RIZOS, C., & HELYER, N., 2006. Audio Nomad. 19th Int. Tech. Meeting of the Satellite Division of the U.S. Inst. of Navigation, Fort Worth, Texas, 26-29 September, 3117-3123. (Download PDF)