An Algorithmic Approach to Quantifying GPS Trajectory Error

The alignment of aerial and satellite imagery with ground sensor data is an ongoing research challenge. In dense urban environments, part of this challenge is induced by the positioning error of Global Positioning System (GPS). Despite the potential for error, many studies use GPS in order to infer road networks because GPS data is inexpensive and can be acquired quickly. Major transit organizations are freely providing data on the real-time position of their buses as well as ground truth route trajectories. This work exploits geospatial open data to construct a database of historical GPS from bus roads. Using this database, the GPS error map along main arteries of major cities can be reconstructed. The extraction of error maps is highly relevant for the planning and the joint exploitation of airborne and ground-based imagery. In this work, we use bus routes in downtown Victoria, BC, Canada and Adelaide, Australia to demonstrate the extraction GPS error maps.