Analysis and correction of the dependency between laser scanner intensity values and range

Abstract

ABSTRACT:Intensity values, which are registered by a terrestrial laser scanner system (TLS) for each point of a 3D point cloud in addition to its coordinates, are affected by the characteristic of the measured object and the parameters of the environment. The backscattered electromagnetic signal is influenced in his strength by the reflectivity of the scanned object surface, the incidence angle, the distance between laser scanner and object and the atmospheric respectively system specific setting of the TLS-measurement. The entity of all influences on the signal can be summarized in the laser range equation of Jelalian 1. For the investigations of this study the named influences where divided into two groups. Group 1 includes the surface specific influences. The second group contains all other influences. The correction of the intensity values from the effects of group 2 theoretically allows the determination of similar materials, using similar intensity values in laser scanner point clouds. In this paper the dependency between laser scanner intensity values and range are investigated on the basis of laser scanner data recorded with a Riegl LMS-Z420i. The results are compared with data from the phase-difference laser scanner Zoller+Fröhlich Imager 5006i.

Remote Sensing to Estimate Saturation Differences of Chosen Building Materials Using Terrestrial Laser Scanner

“…This phenomenon was described by multiple researchers (Blaskow & Schneider, 2014;Kaasalainen et al, 2011;Kukko et al, 2008;Pfeifer et al, 2008;Van Ree, 2006). It is important to remember that when scanning large civil engineering structures values of range (R) and angle of a laser beam hitting an object (α) vary significantly.…”

“…During the data processing it is possible to eliminate the influence of these factors on the value of achieved intensity (for each observed areas) through data standardization. The process of data standardization is thoroughly described in literature (Sasidharan, 2016;Kaasalainen et al, 2011;Blaskow & Schneider, 2014;.…”

Comparison of Time-of-Flight and Phase-Shift TLS Intensity Data for the Diagnostics Measurements of Buildings

“…where P R is the received power, and P th is the detection threshold power of the sensor. The simplified equation for describing the relation between the transmitted signal power (P T ) to the received signal power (P R ) in a TLS is expressed as follows [47]:…”

Damage Detection for Historical Architectures Based on TLS Intensity Data

“…Many studies have found that the intensity data does not follow the LiDAR equation in the near range and different TLS systems may result in different intensity-range relations (Kaasalainen et al, 2011;Fang et al, 2014;. Therefore, most TLS intensity correction studies investigated data-driven method instead of the model-driven one Blaskow and Schneider, 2014).…”