Improving positioning accuracy in WAW location-based services

2008 ◽  
Author(s):  
Jose E. Sanguino ◽  
Filipe Tocha ◽  
Antonio Rodrigues
Keyword(s):  
Location Based Services ◽  
Positioning Accuracy

Mobile GIS - Challenges and Solutions

2011 ◽  
pp. 793-809
Author(s):  
Pramod Sharma ◽  
Devon Nugent
Keyword(s):  
Wireless Networks ◽  
Mobile Devices ◽  
Location Based Services ◽  
Specific Information ◽  
Positioning Accuracy ◽  
Mobile Gis ◽  
Gis Applications ◽  
Potential Market ◽  
Small Screen Devices ◽  
Small Screen

This chapter focuses on Mobile GIS (MGIS), which uses wireless networks and small screen mobile devices (such as PDAs and smartphones) to collect or deliver real time, location specific information and services. Such services can be divided into field and consumer (location based services) GIS applications. The use of wireless networks and small screen devices, introduce a series of challenges, not faced by desktop or wired internet GIS applications. This chapter discusses the challenges faced by mobile GIS (e.g. small screen, bandwidth, positioning accuracy, interoperability, etc.) and the various means of overcoming these problems, including the rapid advances in relevant technologies. Despite the challenges, many efficient and effective Mobile GIS applications have been developed, offering a glimpse of the potential market.

scholarly journals Indoor Positioning on Disparate Commercial Smartphones Using Wi-Fi Access Points Coverage Area

Sensors ◽  
2019 ◽  
Vol 19 (19) ◽  
pp. 4351 ◽  
Author(s):  
Ashraf ◽  
Hur ◽  
Park
Keyword(s):  
Human Mobility ◽  
Indoor Positioning ◽  
Location Based Services ◽  
Indoor Environments ◽  
Coverage Area ◽  
Positioning Accuracy ◽  
Positioning Systems ◽  
Access Points ◽  
Intersection Area ◽  
The Impact

The applications of location-based services require precise location information of a user both indoors and outdoors. Global positioning system’s reduced accuracy for indoor environments necessitated the initiation of Indoor Positioning Systems (IPSs). However, the development of an IPS which can determine the user’s position with heterogeneous smartphones in the same fashion is a challenging problem. The performance of Wi-Fi fingerprinting-based IPSs is degraded by many factors including shadowing, absorption, and interference caused by obstacles, human mobility, and body loss. Moreover, the use of various smartphones and different orientations of the very same smartphone can limit its positioning accuracy as well. As Wi-Fi fingerprinting is based on Received Signal Strength (RSS) vector, it is prone to dynamic intrinsic limitations of radio propagation, including changes over time, and far away locations having similar RSS vector. This article presents a Wi-Fi fingerprinting approach that exploits Wi-Fi Access Points (APs) coverage area and does not utilize the RSS vector. Using the concepts of APs coverage area uniqueness and coverage area overlap, the proposed approach calculates the user’s current position with the help of APs’ intersection area. The experimental results demonstrate that the device dependency can be mitigated by making the fingerprinting database with the proposed approach. The experiments performed at a public place proves that positioning accuracy can also be increased because the proposed approach performs well in dynamic environments with human mobility. The impact of human body loss is studied as well.

scholarly journals Multi-Slot BLE Raw Database for Accurate Positioning in Mixed Indoor/Outdoor Environments

Data ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 67 ◽  
Author(s):  
Fernando J. Aranda ◽  
Felipe Parralejo ◽  
Fernando J. Álvarez ◽  
Joaquín Torres-Sospedra
Keyword(s):  
Signal Strength ◽  
Received Signal Strength ◽  
Low Energy ◽  
Location Based Services ◽  
Positioning System ◽  
Positioning Accuracy ◽  
Bluetooth Low Energy ◽  
Outdoor Environments ◽  
The University

The technologies and sensors embedded in smartphones have contributed to the spread of disruptive applications built on top of Location Based Services (LBSs). Among them, Bluetooth Low Energy (BLE) has been widely adopted for proximity and localization, as it is a simple but efficient positioning technology. This article presents a database of received signal strength measurements (RSSIs) on BLE signals in a real positioning system. The system was deployed on two buildings belonging to the campus of the University of Extremadura in Badajoz. the database is divided into three different deployments, changing in each of them the number of measurement points and the configuration of the BLE beacons. the beacons used in this work can broadcast up to six emission slots simultaneously. Fingerprinting positioning experiments are presented in this work using multiple slots, improving positioning accuracy when compared with the traditional single slot approach.

scholarly journals Demonstration of Three-Dimensional Indoor Visible Light Positioning with Multiple Photodiodes and Reinforcement Learning

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6470
Author(s):  
Zhuo Zhang ◽  
Huayang Chen ◽  
Weikang Zeng ◽  
Xinlong Cao ◽  
Xuezhi Hong ◽  
...  
Keyword(s):  
Reinforcement Learning ◽  
Visible Light ◽  
Three Dimensional ◽  
Two Dimensions ◽  
Location Based Services ◽  
Positioning Accuracy ◽  
The Third ◽  
Basic Model ◽  
3D Space ◽  
3D Positioning

To provide high-quality location-based services in the era of the Internet of Things, visible light positioning (VLP) is considered a promising technology for indoor positioning. In this paper, we study a multi-photodiodes (multi-PDs) three-dimensional (3D) indoor VLP system enhanced by reinforcement learning (RL), which can realize accurate positioning in the 3D space without any off-line training. The basic 3D positioning model is introduced, where without height information of the receiver, the initial height value is first estimated by exploring its relationship with the received signal strength (RSS), and then, the coordinates of the other two dimensions (i.e., X and Y in the horizontal plane) are calculated via trilateration based on the RSS. Two different RL processes, namely RL1 and RL2, are devised to form two methods that further improve horizontal and vertical positioning accuracy, respectively. A combination of RL1 and RL2 as the third proposed method enhances the overall 3D positioning accuracy. The positioning performance of the four presented 3D positioning methods, including the basic model without RL (i.e., Benchmark) and three RL based methods that run on top of the basic model, is evaluated experimentally. Experimental results verify that obviously higher 3D positioning accuracy is achieved by implementing any proposed RL based methods compared with the benchmark. The best performance is obtained when using the third RL based method that runs RL2 and RL1 sequentially. For the testbed that emulates a typical office environment with a height difference between the receiver and the transmitter ranging from 140 cm to 200 cm, an average 3D positioning error of 2.6 cm is reached by the best RL method, demonstrating at least 20% improvement compared to the basic model without performing RL.

scholarly journals CC-DTW: An Accurate Indoor Fingerprinting Localization Using Calibrated Channel State Information and Modified Dynamic Time Warping

Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 1984 ◽  
Author(s):  
Zhongliang Deng ◽  
Xiao Fu ◽  
Qianqian Cheng ◽  
Lingjie Shi ◽  
Wen Liu
Keyword(s):  
Channel State Information ◽  
Dynamic Time Warping ◽  
Local Area Network ◽  
Location Based Services ◽  
Area Network ◽  
Time Warping ◽  
Channel State ◽  
Positioning Accuracy ◽  
State Information ◽  
Dynamic Time

Indoor wireless local area network (WLAN) based positioning technologies have boomed recently because of the huge demands of indoor location-based services (ILBS) and the wide deployment of commercial Wi-Fi devices. Channel state information (CSI) extracted from Wi-Fi signals could be calibrated and utilized as a fine-grained positioning feature for indoor fingerprinting localization. One of the main factors that would restrict the positioning accuracy of fingerprinting systems is the spatial resolution of fingerprints (SRF). This paper mainly focuses on the improvement of SRF for indoor CSI-based positioning and a calibrated CSI feature (CCF) with high SRF is established based on the preprocess of both measured amplitude and phase. In addition, a similarity calculation metric for the proposed CCF is designed based on modified dynamic time warping (MDTW). An indoor fingerprinting method based on CCF and MDTW, named CC-DTW, is then proposed to improve the positioning accuracy in indoors. Experiments are conducted in two indoor office testbeds, and the performances of the proposed CC-DTW, one time-reversal (TR) based approach and one Euclidean distance (ED) based approach are evaluated and discussed. The results show that the SRF of CC-DTW outperforms the TR-based one and the ED-based one in both two testbeds in terms of the receiver operating characteristic (ROC) curve metric, and the area under curve (AUC) metric.

Study on Location Based Services Driven Mobile E-Commerce System

2013 ◽  
Vol 734-737 ◽  
pp. 3214-3219
Author(s):  
Hai Dong Zhong ◽  
Ping Li ◽  
Shao Zhong Zhang ◽  
Wen Ting Yuan ◽  
Xu Dong Zhao ◽  
...  
Keyword(s):  
Mobile Devices ◽  
Mobile Device ◽  
Location Based Services ◽  
Prototype System ◽  
Security Risks ◽  
Privacy And Security ◽  
Positioning Accuracy ◽  
Business Markets ◽  
Key Issues ◽  
Novel Concept

With the tremendous advances in mobile computing and communication capabilities, rapid proliferation of mobile devices, increasing powerful functions, and decreasing device costs, we are seeing a explosively growth in mobile e-commerce in various consumer and business markets. On the basis of analyzing demands of both buyers and seller in mobile e-commerce, the paper put forward a novel concept and technological framework of Location Based Services (LBS) driven mobile e-commerce. Some LBS related functions, in mobile device terminal, of the prototype system based on the architecture put forward are implemented. Also, some key issues of LBS based mobile e-commerce, such as positioning accuracy and new privacy and security risks, are discussed in detail.

An Analysis of Wi-Fi Based Indoor Positioning Accuracy

2011 ◽  
Vol 44 (1) ◽  
pp. 131-137 ◽  
Author(s):  
Gints Jekabsons ◽  
Vadim Kairish ◽  
Vadim Zuravlyov
Keyword(s):  
Low Cost ◽  
Indoor Positioning ◽  
Research Topic ◽  
Location Based Services ◽  
Distinct Advantage ◽  
Positioning Accuracy ◽  
Location Fingerprinting ◽  
Indoor Wireless ◽  
Significant Research ◽  
Increasing Demand

An Analysis of Wi-Fi Based Indoor Positioning AccuracyThe increasing demand for location based services inside buildings has made indoor positioning a significant research topic. This study deals with indoor positioning using the Wireless Ethernet IEEE 802.11 (Wireless Fidelity, Wi-Fi) standard that has a distinct advantage of low cost over other indoor wireless technologies. The aim of this study is to examine several aspects of location fingerprinting based indoor positioning that affect positioning accuracy. Overall, the positioning accuracy achieved in the performed experiments is 2.0 to 2.5 meters.

scholarly journals Combination of Smartphone MEMS Sensors and Environmental Prior Information for Pedestrian Indoor Positioning

Sensors ◽  
2020 ◽  
Vol 20 (8) ◽  
pp. 2263
Author(s):  
Lu Huang ◽  
Hongsheng Li ◽  
Baoguo Yu ◽  
Xingli Gan ◽  
Boyuan Wang ◽  
...  
Keyword(s):  
Large Scale ◽  
Feature Detection ◽  
Turning Point ◽  
Rapid Development ◽  
Calibration Method ◽  
Indoor Positioning ◽  
Location Based Services ◽  
Small Scale ◽  
Localization Algorithm ◽  
Positioning Accuracy

In view of the inability of Global Navigation Satellite System (GNSS) to provide accurate indoor positioning services and the growing demand for location-based services, indoor positioning has become one of the most attractive research areas. Moreover, with the improvement of the smartphone hardware level, the rapid development of deep learning applications on mobile terminals has been promoted. Therefore, this paper borrows relevant ideas to transform indoor positioning problems into problems that can be solved by artificial intelligence algorithms. First, this article reviews the current mainstream pedestrian dead reckoning (PDR) optimization and improvement methods, and based on this, uses the micro-electromechanical systems (MEMS) sensor on a smartphone to achieve better step detection, stride length estimation, and heading estimation modules. In the real environment, an indoor continuous positioning system based on a smartphone is implemented. Then, in order to solve the problem that the PDR algorithm has accumulated errors for a long time, a calibration method is proposed without the need to deploy any additional equipment. An indoor turning point feature detection model based on deep neural network is designed, and the accuracy of turning point detection is 98%. Then, the particle filter algorithm is used to fuse the detected turning point and the PDR positioning result, thereby realizing lightweight cumulative error calibration. In two different experimental environments, the performance of the proposed algorithm and the commonly used localization algorithm are compared through a large number of experiments. In a small-scale indoor office environment, the average positioning accuracy of the algorithm is 0.14 m, and the error less than 1 m is 100%. In a large-scale conference hall environment, the average positioning accuracy of the algorithm is 1.29 m, and 65% of the positioning errors are less than 1.50 m which verifies the effectiveness of the proposed algorithm. The simple and lightweight indoor positioning design scheme proposed in this article is not only easy to popularize, but also provides new ideas for subsequent scientific research in the field of indoor positioning.

Improved Indoor Ultrasonic Positioning for Smartphones Using TDOA

2014 ◽  
Vol 614 ◽  
pp. 484-489 ◽  
Author(s):  
Shuai Su ◽  
Fang Zhao ◽  
Hong Wei Jia
Keyword(s):  
Least Squares ◽  
Weighted Least Squares ◽  
Signal Transmission ◽  
Location Based Services ◽  
Positioning Accuracy ◽  
Straight Line ◽  
Fitting Method ◽  
Commercial Off The Shelf ◽  
Line Fitting ◽  
Innate Ability

With the development of Internet and sensor network, relevant application have a more high desire for the positioning accuracy. Meanwhile, modern smartphones are a great platform for Location Based Services (LBS). While outdoor LBS for smartphones has proven to be very successful, indoor LBS for smartphones has not yet fully developed due to the lack of an accurate positioning technology. We present an accurate indoor positioning approach for commercial off-the-shelf (COTS ) smartphones that uses the innate ability of mobile phones to produce ultrasound, combined with Time-Difference-of-Arrival (TDOA) asynchronous trilateration. Ultrasonic signal transmission will cause ranging error, which may affect the precision of positioning. In order to solve this problem, this paper uses least squares straight line fitting method to compensate error and fix distance, then, uses weighted least squares methods to improve the positioning accuracy of the system.

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