A Localization System for GPS-free Navigation Scenarios

Localization is crucial to mobile navigation, which mainly depends on satellite navigation systems such as GPS. Unfortunately, sometimes GPS localization might be missing due to hardware failure or the urban canyon effect. Network localization is a promising way to improve localization experience for users under these conditions. However, there has not been any report on the large-scale applications of network localization methods to GPS-free outdoor scenarios. In this paper, we describe the challenges and build a novel navigation fingerprint based localization system, which fuses road network information and Wi-Fi signals scanned outdoors. With large amount of navigation trajectories as supervised information, we train a ranking model to obtain a reasonable metric for localization. The localization system has been deployed in Tencent Map, improving navigation accuracy in GPS-free outdoor scenarios for 1.6 million users.