Open source in field geology: a QGIS-mate Android compass

BeeDip is a digital geological compass developed by students and researchers of Urbino University under open source license (GPL) dedicated to the open source QGIS software. The app can be installed in any Android smartphone. Previous apps are able to measure different kind of geological data, but all of them keep a “closed” code (Weng and Grigsby, 2012; Lee et al., 2013). The connection with QGIS is guaranteed by an homonymous plug-in (Phyton developed) which enable the export/import of data and maps from and to the GIS project. The used file format is Geopackage (OGC, 2017), under open source MIT license. This allows to import in the app any georeferenced and tiled geotiff map file, enabling the off-line and custom map visualisation with appropriate symbols and labels. Also the data transfer from the app to QGIS has been facilitated. The digital compass can record surface and line measurements, adding other complementary data/metadata and organising them by projects. Tests and comparisons have been performed to assess the validity of this system in the lab and in the field concluding that the data acquisition is fast and simple, but devices can be calibrated and the accuracy depends mainly on built-in sensors (Novalowa and Pavlis, 2017). The app and the plug-in are open to any contribution of developers and users.