the earth’s gravity field dedicated missions provide homogeneous and uniformly accurate information on the long wavelengths of the earth’s gravity field. many different global geopotential models have introduced by earth and space research centers during the last years. the geopotential models derived from the grace satellite measurements are compared with the other models at different frequenc...

A novel method of map matching using the Global Positioning System (GPS) has been developed for civilian use, which uses digital mapping data to infer the <100 meters systematic position errors which result largely from “selective availability” (S/A) imposed by the U.S. military. A method of rapidly detecting inappropriate road centrelines from the set of all possible road centre-lines that a v...

Recording the movement of objects or persons with GPS-technology has been widely adopted. So called GPS traces are used for enriching travel diaries (Wolf et al. 2001), for learning significant places (Ashbrook and Starner 2003), for monitoring animal movement (Steiner et al. 2000) or for building road maps (Cao and Krumm 2009). While all of the mentioned applications rely on GPS traces, the me...