Radiometric Calibration of Multi-Wavelength Airborne Laser Scanning Data

Abstract

Commission VII, WG VII/7 ABSTRACT:Airborne laser scanning (ALS) is a widely used technique for the sampling of the earth's surface. Nowadays a wide range of ALS sensor systems with different technical specifications can be found. One parameter is the laser wavelength which leads to a sensitivity for the wavelength dependent backscatter characteristic of sensed surfaces. Current ALS sensors usually record next to the geometric information additional information on the recorded signal strength of each echo. In order to utilize this information for the study of the backscatter characteristic of the sensed surface, radiometric calibration is essential. This paper focuses on the radiometric calibration of multi-wavelength ALS data and is based on previous work on the topic of radiometric calibration of monochromatic (single-wavelength) ALS data. After a short introduction the theory and whole workflow for calibrating ALS data radiometrically based on in-situ reference surfaces is presented. Furthermore, it is demonstrated that this approach for the monochromatic calibration can be used for each channel of multi-wavelength ALS data. The resulting active multi-channel radiometric image does not have any shadows and from a geometric viewpoint the position of the objects on top of the terrain surface is not altered (the result is a multi-channel true orthophoto). Within this paper the approach is demonstrated by three different single-wavelength ALS data acquisition campaigns (532nm, 1064nm and 1550nm) covering the area of the city Horn (Austria). The results and practical issues are discussed.

Evaluating the Potential of Multispectral Airborne Lidar for Topographic Mapping and Land Cover Classification

“…Briese et al, 2012Briese et al, , 2013, or the merging of ortho photos to the point cloud acquired at different time steps. Compared to optical imagery, it is also influenced by comparable effects such as mixed pixels (geometrical channel grouping) or sun illumination (surface roughness and laser beam interaction).…”

“…flight trajectory or atmospheric conditions) and ground truth data are available, no detailed analysis on beam incidence angle effects as presented by Jutzi and Gross (2010) or radiometric calibration approaches (e.g. Briese et al, 2012) could be conducted. All processing is done with the System for Automated Geoscientific Analysis (SAGA, Conrad et al, 2015) and the extension Laserdata Information System (LIS, Laserdata, 2015, Rieg et al, 2014.…”

“…A comprehensive overview on the concept of multiwavelength ALS has been presented by Pfennigbauer and Ullrich (2011). Based on this study, one of the first multiwavelength LiDAR ALS experiments for topographic land surface and object differentiation has been conducted by Briese et al (2012Briese et al ( , 2013. They assemble FWF ALS point clouds from three independent flight missions using RIEGL scanners operating in different wavelengths (532 nm, 1,064 nm, 1,550 nm).…”

Airborne Dual-Wavelength LiDAR Data for Classifying Land Cover

“…The radiometric correction for each LiDAR system has been determined [30]. Further correction of dual-wavelength LiDAR systems will be considered for advanced usage [31]. The accuracy of the collected LiDAR data can be verified by comparing with independently surveyed ground control points.…”

Capability Assessment and Performance Metrics for the Titan Multispectral Mapping Lidar

“…Performing more complex intensity corrections and ground cover classification experiments is outside of the scope of this paper. However, it is worth mentioning that other research groups are performing such experiments based on Titan data with very promising results [29,35], while others have been actively working on the field of radiometric calibration of single and multispectral lidar intensities [4,6,7,17,36].…”