SHOOTING BUILDING FACADES USING REMOTELY PILOTED VEHICLE

Abstract

Facades survey in urban agglomerations has its own characteristics. Constrained conditions for performing geodetic measurements, work on shooting facades from the ground have many dead zones,, with vertical angles exceeding 45 °, which can lead to a decrease in the accuracy of measurement results. This entails the need to take into account a number of instrumental errors of the electronic total station when performing surveys with a semi-receiver. The use of a geodetic measurement method is not always possible due to the lack of an acceptable installation location for an electronic total station, for example, when monitoring buildings, dams, bridges, etc. Under these conditions, it is reasonable to use aerial photography from unmanned aerial vehicles (UAVs) rotary type — quadcopter. The software products intended for processing data from UAV makes it possible to obtain both orthophotoplans and more promising pseudo-spatial models with a real image of objects that can be observed and measured on a monitor screen - three-dimensional realistic models of buildings. The article presents the results of the facade survey of the structure under construction, obtained by a geodetic method using an electronic total station and photogrammetric method using а DJI Phantom 4 pro unmanned aerial vehicle. The errors of obtaining the coordinates of the reference points necessary for photogrammetric processing are considered. The technology of performance of works realized by the photogrammetric method is given and calculation of the optimal parameters of aerial photography is resulted. The results of deviations from the design position of the parts of the facade obtained by the orthophotomap are given. The maximum deviation value of the angle of the window opening in the plane of the facade was 102 mm, which made it possible to quickly identify rough construction errors. Deviations less than 25 mm accounted for 85% of the measurements made. A comparative assessment of two methods showed a number of advantages of using UAVs for facade surveys compared to the traditional geodetic survey by an electronic total station.