An accuracy improving method for three dimensional location systems

GPS is especially suitable for use of location systems in wide open areas, but the availability of GPS is limited in highly built-up areas and mountain areas due to the nature of satellite communications. To extend the apparent coverage of the GPS system from a pedestrian's perspective in the mountain areas, the dead reckoning system is generally used during the transit of pedestrians through the non-GPS mountain area. The speeds of pedestrians change according to the inclination of the ground in the slanted areas such as mountains. To reduce location measurement errors, we propose a calculation method for improving accuracy of 3D location decisions using the speeds of pedestrians based on the inclination of the ground. The angle of the inclination is obtained using the contour lines of the mountain and the location of the pedestrians is calculated using this speeds based on the inclination. The simulation results show that this proposed system is more accurate in comparison with the existing location system that uses the average speeds of pedestrians.