r.survey.py

r.survey is aimed at earth surface analysis. It is useful for evaluating the visibility (in terms of 3D Distance, Solid Angle and orientation of the terrain respect to the line of sight) of features lying on the terrain slope, like landslides, road cuts, minor vegetation, mining activity, geological outcrops, surface pipelines, parking areas, solar panels plants, burned areas, etc. Depending on the purpose of the study, one can be interested in searching the closest position to observe a given territory while for others, having a frontal view can be more relevant. In some cases, the objective could be the combined balance between the closest and the most frontal view, in order to evaluate how much of the human field of view is occupied by a given object (solid angle). r.survey is deeply based on the powerfull r.viewshed GRASS GIS module. r.survey wants to provide the user the necessary information to answer questions such as: In a survey trip, from how many places is something visible? During a field work, which place would be the best position to observe a given point/area (according to the distance, the angle or both)? Which portion of the territory is visible along a survey path/flight? Are objects of a given size visible from a survey path/flight?