Integration of terrestrial laser scanning and structure from motion for the assessment of industrial chimney geometry

The idea of this study is to attempt to combine the TLS and SfM methods for the measurement of a 120 m industrial chimney. The integrated model should have full point cloud coverage, maintaining an accuracy comparable to laser scanning. TLS was used to construct a coherent model of the lower parts of the chimney, to which the point cloud from the SfM method was then attached. For full point coverage, internal consistency of a few millimeters was achieved for each method and the external consistency was around 10 mm. As elevation increased causing uneven loss of scanner range, the consistency of the TLS deteriorated. However, integration of both measurement methods was possible even in areas of partial point cloud coverage. Sufficient coverage occurred on the length of about 55 m and allowed to integrate clouds with an average error of 13 mm.