Civil Engineering, Architecture and Structural Materials

Biography

Biography: Czesław Suchocki

Abstract

Building information modelling (BIM) is a still evolving technology for storing and exchanging knowledge about buildings. The success of BIM implementation relies on the up-to-date and accurate building models. However, the building models very often can be inaccurate and out-of-date. Obtaining the up-to-date information about the technical condition of architectural structures allows the terrestrial laser scanning techniques (TLS). The product of TLS measurements is a 3D (XYZ) point cloud captured with high-resolution and high-accuracy. Apart from 3D coordinates, TLS can register the intensity of a laser beam reflected by an object. The intensity value depends mainly on the physical and chemical properties of examined areas. The intensity can provide support for defect detection in building walls. For instance, detection of moisture, walls weathering, salt blooming, bio-deterioration, also cracks and cavities. Thus, TLS dataset allows one to build 3D building models, as well as detect building defects. Geometric dataset can also be combined with a real photo taken by TLS. Manufacturers of TLS use two different principles for distance measurement between the sensor system and its target. The first principle is time-of-flight (TOF) and second is phase-shift (PS). The power of the energy in both types of rangefinders might be absorbed or reflected in a slightly different way.

This paper presents the radiometric information analysis of point cloud captured by two different types terrestrial laser scanner (TOF and PS) in the context diagnostics measurements of buildings and structures.  The test results clearly show that intensity data captured by PS scanners provide much more useful information about the surface imperfections of buildings compared to the intensity data captured by TOF scanners.