An efficient outdoor localization method for smartphones

Location has become a key service for smartphone applications. With the help of inertial navigation unit integrated into smartphones, such as accelerometer and compass, we can provide reliable and accurate localization service, which overcomes huge energy consumption of GPS and rough location accuracy of systems based on GSM or Wi-Fi. In this paper, we present a reliable and energy-efficient localization system using inertial sensors commonly found on today´s smartphone. Reliable algorithms for displacement determination and heading direction have been developed. Then Vincenty´s formulae are employed to calculate the latitude and longitude of the endpoint. In order to prevent accumulated error, location correction mechanism based on local map information and A-GPS is introduced. Measurements on Samsung I9100 and evaluation in the real condition confirm anticipated benefits. Results show that ACMG uses 24.7% less power consumption than GPS, and get a mean location accuracy of less than 6.7m in our test.