Towards the production of digital terrain models from volunteered GPS trajectories

Abstract

There currently exists a wide variety of online resources providing mapping infrastructures and geographic information. Most web-based map services, such as Google Maps, Yahoo! Maps and Bing Maps, are mostly based on data that is collected by authoritative mapping agencies. Alternatively, some relatively new web-map services, such as OpenStreetMap (OSM) and Wikimapia, are mostly based on volunteered data collected by the public (e.g. crowdsourced mapping). Although such volunteered-based map services platforms show an increasing planimetric (2D) accuracy, completeness and update-rate of their mapping infrastructure, surprisingly enough, there is a lack of comparable data and accuracy measures in respect to the third dimension, i.e. height; more specifically, the topographic representation that is based on the volunteered collected data. Most of these web services still rely on existing open-source authoritative topographic infrastructures, and not on data collected by the volunteers. Moreover, topographic information that is open to the public and is free to use, e.g. advanced spaceborne thermal emission and reflection radiometer and shuttle radar topography mission, is regularly available with relatively low height accuracy (not better than 5 m) and low planimetric resolution (over 30 m). Volunteered data, on the other hand, collected by individuals that are situated ‘all over’ the globe can offer with new capabilities and data characteristics having potentially higher qualities. This research proposes to examine the feasibility of using crowdsourced volunteered geographic information working paradigm for the task of producing a reliable digital terrain model (DTM) infrastructure for general use. This is achieved by collecting GPS observations that are available from VG data sources, while applying a 2D Kalman filter-based algorithm, aimed at reducing noise and ambiguities. This paper presents this methodology, with preliminary analysis results achieved by this implementation, showing the feasibility of this working methodology, having good results and accuracy of the DTM generated.