THREE-DIMENSIONAL DIGITIZATION OF ENVIRONMENTS AND BUILDINGS FOR SMART CITY APPLICATIONS
Keywords: Point cloud, Three-dimensional, Smart City, GIS, LiDAR, Photogrammetry
Abstract. The smart cities that promise a sustainable future cannot be thought of independently from the spatial information infrastructure. It is very important to keep the spatial data infrastructure up-to-date for guidance and information in smart city applications (SCA). Easy and low-cost acquisition is an important factor in updating spatial data. Today, there are many measurement techniques to collecting 3-D spatial data of urban areas and land topography. On the other hand, indoor measurement and 3-D modelling techniques are used in the creation of building information modelling (BIM). In this study, measurement techniques that provide 3-D point cloud data to SCA are examined. Consequently, image based photogrammetry and dense matching methods enable low cost measurement than LiDAR based active measurement. The active 3-D measurement techniques have high accuracy especially for mid and long ranges. The LiDAR, that can be applied at day or night time, offer more opportunity to performing SCA like autonomous vehicle and robotic navigations. Nevertheless, LiDAR can only capture structure, not texture, and therefore has limits to the types of data that it can capture. The LiDAR and image based methods are complement to each other in 3-D reality capture. The 3-D measurement techniques are exploited according to SCA as alone or together.