A survey of hybridisation methods of GNSS and wireless LAN based positioning system <s> Introduction <s> This survey and taxonomy of location systems for mobile-computing applications describes a spectrum of current products and explores the latest in the field. To make sense of this domain, we have developed a taxonomy to help developers of location-aware applications better evaluate their options when choosing a location-sensing system. The taxonomy may also aid researchers in identifying opportunities for new location-sensing techniques. <s> BIB001 </s> A survey of hybridisation methods of GNSS and wireless LAN based positioning system <s> Introduction <s> Wireless positioning has attracted much research attention and has become increasingly important in recent years. Wireless positioning has been found very useful for other applications besides E911 service, ranging from vehicle navigation and network optimization to resource management and automated billing. Although many positioning devices and services are currently available, it is necessary to develop an integrated and seamless positioning platform to provide a uniform solution for different network configurations. This article surveys the state-of-the-art positioning designs, focusing specifically on signal processing techniques in network-aided positioning. It serves as a tutorial for researchers and engineers interested in this rapidly growing field. It also provides new directions for future research for those who have been working in this field for many years. <s> BIB002 </s> A survey of hybridisation methods of GNSS and wireless LAN based positioning system <s> Introduction <s> Wireless indoor positioning systems have become very popular in recent years. These systems have been successfully used in many applications such as asset tracking and inventory management. This paper provides an overview of the existing wireless indoor positioning solutions and attempts to classify different techniques and systems. Three typical location estimation schemes of triangulation, scene analysis, and proximity are analyzed. We also discuss location fingerprinting in detail since it is used in most current system or solutions. We then examine a set of properties by which location systems are evaluated, and apply this evaluation method to survey a number of existing systems. Comprehensive performance comparisons including accuracy, precision, complexity, scalability, robustness, and cost are presented. <s> BIB003 </s> A survey of hybridisation methods of GNSS and wireless LAN based positioning system <s> Introduction <s> Foreword. Acknowledgements. Preface. Chapter 1. A brief history of navigation and positioning. 1.1 The first age of navigation. 1.2 The age of the great navigators. 1.3 Cartography, lighthouses and astronomical positioning. 1.4 The radio age. 1.5 The first terrestrial positioning systems. 1.6 The era of artificial satellites. 1.7 Real-time satellite navigation constellations today. 1.8 Exercises. Bibliography. Chapter 2. A brief explanation of the early techniques of positioning. 2.1 Discovering the world. 2.2 The first age of navigation and the longitude problem. 2.3 The first optical based calculation techniques. 2.4 The first terrestrial radio based systems. 2.5 The first navigation satellite systems: TRANSIT and PARUS/TSIKADA. 2.6 The second generation of navigation satellite systems: GPS, GLONASS and Galileo. 2.7 The forthcoming third generation of navigation satellite systems: QZSS and COMPASS. 2.8 Representing the world. 2.9 Exercises. Bibliography Chapter 3. Development, deployment and current status of satellite based navigation systems. 3.1 Strategic, economical and political aspects. 3.2 The global positioning satellite systems: GPS, GLONASS and Galileo. 3.2.1 The Global Positioning System : GPS. 3.2.2 The GLONASS. 3.2.3 Galileo. 3.3 The GNSS1: EGNOS, WAAS and MSAS. 3.4 The other satellite based systems. 3.5 Differential satellite based commercial services. 3.6 Exercises. Bibliography. Chapter 4. Non-GNSS positioning systems and techniques for outdoors. 4.1 Introduction (large area without contact or wireless systems). 4.2 The optical systems. 4.3 The terrestrial radio systems. 4.4 The satellite radio systems. 4.5 Non-radio based systems. 4.6 Exercises. Bibliography. Chapter 5. GNSS system descriptions. 5.1 System description. 5.2 Summary and comparison of the three systems. 5.3 Basics of GNSS positioning parameters. 5.4 Introduction to error sources. 5.5 Concepts of differential approaches. 5.6 SBAS system description (WAAS and EGNOS). 5.7 Exercises. Bibliography. Chapter 6. GNSS navigation signals: description and details. 6.1 Navigation signal structures and modulations for GPS, GLONASS and Galileo. 6.2 Some explanations of the concepts and details of the codes. 6.3 Mathematical formulation of the signals. 6.4 Summary and comparison of the 3 systems. 6.5 Developments. 6.6 Error sources. 6.7 Time reference systems. 6.8 Exercises. Bibliography. Chapter 7. Acquisition and tracking of GNSS signals. 7.1 Transmission part. 7.2 Receiver architectures. 7.3 Measurement techniques. 7.4 Exercises. Bibliography. Chapter 8. Techniques for calculating positions. 8.1 Calculating the PVT solution. 8.2 Satellite's position computations. 8.3 Quantified estimation of errors. 8.4 Impact of pseudo range errors on the computed positioning. 8.5 Impact of geometrical distribution of satellites and receiver (notion of DOP). 8.6 Benefits of augmentation systems. 8.7 Discussion on interoperability and integrity. 8.8 Effect of multipath on the navigation solution. 8.9 Exercises. Bibliography. Chapter 9. Indoor positioning problem and main techniques (Non-GNSS). 9.1 General introduction to indoor positioning. 9.2 A brief review of possible techniques. 9.3 Network of sensors. 9.4 Local area telecommunication systems. 9.5 Wide-area telecommunication systems. 9.6 Inertial systems. 9.7 Recap tables and global comparisons. 9.8 Exercises. Bibliography. Chapter 10. GNSS-based indoor positioning and a summary of indoor techniques. 10.1 HS-GNSS. 10.2 A-GNSS. 10.3 Hybridization. 10.4 Pseudolites. 10.5 Repeaters. 10.6 Recap tables and comparisons. 10.7 Possible evolutions with availability of the future signals. 10.8 Exercises. Bibliography. Chapter 11. Applications of modern geographical positioning systems. 11.1 Introduction. 11.2 A chronological review of the past evolution of applications. 11.3 Individual applications. 11.4 Scientific applications. 11.5 Applications for public regulatory forces. 11.6 Systems under development. 11.7 Classifications of applications. 11.8 Privacy issues. 11.9 Current receivers and systems. 11.10 Conclusion and discussion. 11.11 Exercises. Bibliography. Chapter 12. The forthcoming revolution. 12.1 Time and space. 12.2 Development of current applications. 12.3 The possible revolution of everybody's daily life. 12.4 Possible technical positioning approaches and methods for the future. 12.5 Conclusion. 12.6 Exercises. Bibliography. Index. <s> BIB004 </s> A survey of hybridisation methods of GNSS and wireless LAN based positioning system <s> Introduction <s> The 3G iPhone was the first consumer device to provide a seamless integration of three positioning technologies: Assisted GPS (A-GPS), WiFi positioning and cellular network positioning. This study presents an evaluation of the accuracy of locations obtained using these three positioning modes on the 3G iPhone. A-GPS locations were validated using surveyed benchmarks and compared to a traditional low-cost GPS receiver running simultaneously. WiFi and cellular positions for indoor locations were validated using high resolution orthophotography. Results indicate that A-GPS locations obtained using the 3G iPhone are much less accurate than those from regular autonomous GPS units (average median error of 8 m for ten 20-minute field tests) but appear sufficient for most Location Based Services (LBS). WiFi locations using the 3G iPhone are much less accurate (median error of 74 m for 58 observations) and fail to meet the published accuracy specifications. Positional errors in WiFi also reveal erratic spatial patterns resulting from the design of the calibration effort underlying the WiFi positioning system. Cellular positioning using the 3G iPhone is the least accurate positioning method (median error of 600 m for 64 observations), consistent with previous studies. Pros and cons of the three positioning technologies are presented in terms of coverage, accuracy and reliability, followed by a discussion of the implications for LBS using the 3G iPhone and similar mobile devices. <s> BIB005 </s> A survey of hybridisation methods of GNSS and wireless LAN based positioning system <s> Introduction <s> GPS is now widely accepted as a reliable, available and accurate source of positioning, able to operate across the globe. However, it generally requires at least four satellites to be in view of the receiver, in order to resolve the three co-ordinates of the receiver, and the local receiver time offset. In indoor environments or urban canyons, this requirement can often not be achieved, as walls or tall buildings block the signals emitted by the satellites. Developing alternative positioning systems in such environments has attracted a lot of research in the past few years. In this context, Wi-Fi based positioning systems have emerged as being accurate enough for most users and most importantly because they don’t require any additional hardware or infrastructure. However, such systems fail to reach the same level of accuracy as GPS. The ultimate goal of ubiquitous positioning would be to combine these two technologies so that an accurate position can be delivered, even in poor GPS environments. This paper will examine a method to combine a Wi-Fi obtained position with the output of a two satellite positioning algorithm developed at the University of New South Wales. It will first explore the performances that can be expected from both systems, and then show that better results are obtained when combining both. Tests were conducted using data collected from the CBD area of Sydney and a rooftop mounted GPS antenna in UNSW. <s> BIB006 </s> A survey of hybridisation methods of GNSS and wireless LAN based positioning system <s> Introduction <s> It is known that satellite radiolocalization was born in the military environment and was originally conceived for defense purposes. Nevertheless, the commercial explosion (dated to 20 years ago) of global positioning system (GPS) in the civil market (automotive, tourism, etc.) significantly changed the original perspectives of this technology. Another big change is expected when other global navigation satellite systems (GNSSs) such as the European Galileo or the Chinese COMPASS become operational and commercial. In fact, modern GNSSs are conceived principally for the civil market (at the opposite of GPS, whose civil employment is given as a sort of “kind gift,” with lower performance than that one granted to military users). The scope of this paper is to provide readers with a clear focus about the potentialities of current and forthcoming GNSSs and associated technologies in a renewed mass-market perspective. The paper also opens a window to the future of radiolocalization technology beyond GPS and GNSS, dealing with the role of digital signal processing and software-defined radio (SDR) in next-generation navigation systems and with the seamless integration of satellite-based navigation with other technologies in order to provide reliable position information also in hostile environments. <s> BIB007
The exponentially emerging mobile device market has created a vast demand of location based services (LBS). For many of these applications a seamless indoor/outdoor, a really ubiquitous localisation system is crucial. Outdoors, the NAVSTAR GPS is filling that role since 20 years and many advances in the development GNSSs towards localisation in urban canyons and indoors have been made BIB007  BIB004 . The sensitivity could be increased, including the development of specialised high-sensitivity GNSS (HS-GNSS) receiver; multiple constellations are available nowadays, increasing the coverage; multiple frequencies can be used to mitigate ionospheric influences, and several augmentation systems have been developed in order to improve accuracy and the time-to-first-fix (TTFF). However, a robust indoor localisation solely based on GNSS is still not possible BIB005 . Much less when referring to LBS, which rely on a large number of users needing affordable and portable devices. Hence, it is widely suggested to use additional sensor information * Corresponding author. E-mail: philipp.richter@uaq.mx, Tel.: +52 1921200 6023, Fax: +52 1921200 6006. from inertial measurement systems or wireless communication systems to overcome that problem BIB007 BIB006 BIB003 BIB002 . For indoor localisation several technologies have been investigated BIB001 BIB003 BIB002 , from whose a localisation technology based on the IEEE 802.11 standard for implementing WLANs, seems to be the most promising approach  BIB004 providing a good tradeoff between accuracy, scalability, robustness, complexity, and costs. Moreover, WLAN positioning systems and GNSSs have complementary characteristics. A GNSS is dependent on line-of-sight conditions and works best in open areas. IEEE 802.11 signals penetrate objects and walls and especially the fingerprinting positioning technique, a pattern recognition method, benefits from an irregular signal strength distribution caused by signal shadowing, scattering and so on. The biggest advantage of using a localisation based on WLAN, is probably the already existing infrastructure and a transceiver chip in every modern mobile device. By combining these two positioning techniques rigorously, the coverage area and robustness is increased. Such a system can provide a seamless and ubiquitous localisation. This work intends to summarise, categorise and compare existing data fusion techniques of GNSS and WPS. It does not focus on how sensory data is processed to derive directly a position, rather how data is fused to obtain a position. The paper is organised as follows. An overview of GNSS, how WLAN can be employed as positioning system, and of hybridisation schemes in general is given in Section 2. In Section 3 works are briefly presented, that fuse data of GNSS and WPS. The presentation of these approaches is arranged with respect to the level at which the data fusion is accomplished. In Section 4 the performance of the categories is assessed with respect to accuracy, precision, robustness, complexity and cost. A conclusion is drawn in Section 5 and an outlook can be found in Section 6.