Improving cooperative trajectory mapping applications with encounter-based error correction

Cooperative trajectory mapping is an emerging technique that allows users to create such a map by using data that is collected from each other’s mobile phones. This technique has been proposed for many applications, such as people localization, public transportation tracking, and traffic monitoring. Unlike the traditional GPS, cooperative trajectory mapping only requires information about the departure distance and moving direction from the previously reported position. This avoids problems like the high energy consumption of GPS and weak GPS signals in indoor conditions. However, the new technique also brings about other problems, such as measurement errors in cooperative trajectory mapping, which is when a measurement error causes the spatial relations among users to be wrong. We propose an encounter-based error correction algorithm to efficiently reduce measurement errors. Extensive simulation experiments are performed to validate our solutions.