Beyond horizontal location context

Abstract

Accurate estimation of elevation is important for many location based services. Although, it is possible to obtain altitude from GPS, its accuracy is unreliable and applicable in outdoors only. It is possible to use barometers on smartphones to estimate elevation in both indoor and outdoor scenarios. To this end, we proposed an integrated framework to provide ubiquitous and accurate elevation measurement using smartphones. Experiments conducted in both indoor and outdoor with different geographical characteristics reveal that our system can provide elevation with an error less than 5 meters in 90 % of the cases and less than 3 meters in 75 % of the cases, which is sufficient for most practical applications.

Creating Immersive Virtual Environments Based on Open Geospatial Data and Game Engines

“…A DEM contains structured information about the variation of terrain heights in a specified area. Common measures used to create DEMs include airplane and satellite-based aerial photography and remote sensors, barometers or tachymeters (Frolind and Ulander 2002;Korsgaard et al 2016;Liu et al 2014;Pichon et al 2016). The quality of a DEM is reflected in three parameters: the reliability of the measures used to assess the terrain height and the associated location, the spatial data resolution, and the variation of distance between the data points.…”

“…However, not all measures are equally appropriate to create DEMs covering large areas with a high spatial resolution. Theoretically, it is possible to create a DEM only with a smartphone that has GPS receiver and a barometer (Liu et al 2014). However, this would require a time-consuming systematic and fine-meshed traversing across the complete selected area.…”

Deriving incline values for street networks from voluntarily collected GPS traces

“…With 27 m, the overall RMSE is slightly worse than 15-20 m as found out in previous studies (Liu et al 2014;Zhang, Thiemann, and Sester 2010). A possible reason may be that crowdsourced traces are prone to be recorded under heterogeneous conditions.…”

“…Current mobile devices that are equipped with lowcost GPS receivers have a horizontal accuracy of 5-10 m and a vertical accuracy of up to 25 m (Liu et al 2014). The relatively poor vertical accuracy is explained by the constellation of satellites (cf.…”