Georeferenced cartography dataset of the La Fossa crater fumarolic field at Vulcano Island (Aeolian Archipelago, Italy): conversion and comparison of data from local to global positioning methods

摘要

The present study illustrates the procedures applied for the coordinatesystem conversion of the historical fumarole positions at La Fossa crater,to allow their comparison with newly acquired global positioning system(GPS) data. Due to the absence of ground control points in the field and onboth the old Gauss Boaga and the new UTM WGS 1984 maps, we had tomodel the transformation errors between the two systems using differentialGPS techniques. Once corrected, the maps show a residual Easting shifting,due to erroneous georeferencing of the original base maps; this is correctedby morphological comparative methods. The good correspondence betweenthe corrected positions of the historical data and the results of the newGPS survey that was carried out in 2009 highlights the good quality of theold surveys, although they were carried out without the use of accuratetopographical instruments.