Improving Accuracy of WiFi Positioning System by Using Geographical Information System (GIS)

WiFi positioning system with knowledge of GIS can achieve higher accuracy in terms of distance error comparing with the one without it. Positioning algorithm expectedly gets rid of unlikely crossing area in the region while selecting others. Minimization of crossing area determination with constraint of geographical information is a key contribution. Proper placement of access points in service area is another issue of concern yielding the same consequence as optimal coordinate fitting. Learning process for determining environment characteristics is essential to enable accurate calculation on distance from measured signal strength. Variation of obstructions in one environment can mainly reflect inconsistent profile, especially for indoor environment