The State of the World’s Cadastral System
More than 70% of the world's land rights are unregistered and not part of a cadastral system. This makes establishing land tenure difficult, and in many cases impossible. Mapping the boundaries of land rights, creating a complete cadastral system, and being able to keep it up to date, is a top priority in land administration. Multiple challenges exist to achieving this priority, however, low cost and fast cadastral survey and mapping techniques can overcome many of these.
Indirect mapping techniques are based on delineation of visible cadastral boundaries from high-resolution remote sensing images. The application of image-based cadastral mapping is based on the recognition that many cadastral boundaries coincide with natural or man-made boundaries, such as hedges, land cover boundaries, building walls, roads, etc., and can be easily identified from remote sensing or UAV imagery.
Apart from high-visibility UAV imagery, many previous case studies have reported manual delineation and a limited number of studies have investigated the automatic approach to extract visible cadastral boundaries. Mainly, customized image segmentation and edge detection algorithms have been used to automate cadastral mapping.