An all too often underestimated step in the workflow of a UAV mapping operation is the extraction of features of interest in vector format. Structure from Motion and Lidar give us unprecedented density in point clouds to better represent the shapes we are interested in. While that density helps to define edges and planes accurately, it comes with the big data burdens – heavy processing, lots of memory and patience on the part of the operator – for which clients of geo-spatial services are often not well equipped. You can’t just dump a couple of million faces in a TIN into the old CAD program or GIS without suffocating it and frustrating your end-client!
That’s where micro-tasked capturing of selected details come in. For this purpose we can recommend the use of Virtual Surveyor Tools, a program embedded in Terra Explorer Plus and written by GeoID BV in Leuven, Belgium. It allows for accurate placing of vertices in an easily navigable drone created virtual world where the operator can position himself at optimal vantage points from which he has the best perspective. Captured features (points, poly-lines and polygons in XYZ) can be saved in user defined layers for export in dxf format. If done correctly, the end product is a high octane distilled vector data set which is much more easily digested in end-user applications.