Traditionally, progress monitoring of a construction site is carried out by multiple visual observations and manual records of the actual state. For automation of this procedure digital methods for comparison of the as-planned state and as-built state are proposed. This task can be performed by comparing a 4D Building Information Model (BIM) to actual acquired photogrammetric point clouds. A continuous monitoring requires a frequent acquisition and subsequent comparison of co-registered point clouds. We propose for this task a procedure consisting of three steps: (1) mounting photogrammetric ground control markers in the coordinate system of the construction site; (2) creating an image block using these control points only in this initial step; (3) registration of images from subsequent acquisitions based on 2D-features only. For evaluation, we have investigated two scenarios and two acquisitions techniques. Using a hand-held camera and an Unmanned Aerial Vehicle in total 14 acquisitions were recorded. In both scenarios the consecutive registration was successful and shows deviations of 3–5 cm of planes derived from the point clouds in relation to planes of the BIM.     «

Traditionally, progress monitoring of a construction site is carried out by multiple visual observations and manual records of the actual state. For automation of this procedure digital methods for comparison of the as-planned state and as-built state are proposed. This task can be performed by comparing a 4D Building Information Model (BIM) to actual acquired photogrammetric point clouds. A continuous monitoring requires a frequent acquisition and subsequent comparison of co-registered point cl...     »