High-Accuracy Differential Tracking of Low-Cost GPS Receivers

TitleHigh-Accuracy Differential Tracking of Low-Cost GPS Receivers
Publication TypeConference Paper
Year of Publication2013
AuthorsHedgecock, W., M. Maroti, J. Sallai, P. Volgyesi, and A. Ledeczi
Conference NameACM 11th International Conference on Mobile Systems, Applications, and Services (MobiSys '13)
Date Published06/2013
Conference LocationTaipei, Taiwan

In many mobile wireless applications such as the automated driving of cars, formation flying of unmanned air vehicles, and source localization or target tracking with wireless sensor networks, it is more important to know the precise relative locations of nodes than their absolute coordinates. GPS, the most ubiquitous localization system available, generally provides only absolute coordinates. Furthermore, low-cost receivers can exhibit tens of meters of error or worse in challenging RF environments. This paper presents an approach that uses GPS to derive relative location information for multiple receivers. Nodes in a network share their raw satellite measurements and use this data to track the relative motions of neighboring nodes as opposed to computing their own absolute coordinates. The system has been implemented using a network of Android phones equipped with a custom Bluetooth headset and integrated GPS chip to provide raw measurement data. Our evaluation shows that centimeter-scale tracking accuracy at an update rate of 1 Hz is possible under various conditions with the presented technique. This is more than an order of magnitude more accurate than simply taking the difference of reported absolute node coordinates or other simplistic approaches due to the presence of uncorrelated measurement errors.

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