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C. Briese, M. Pfennigbauer, A. Ullrich, N. Pfeifer:
"Radiometric Analysis Of Multi-Wavelength Airborne Laser Scanning Data";
Talk: Europen Lidar Mapping Forum (ELMF), Salzburg; 2012-12-04 - 2012-12-05.

Airborne laser scanning (ALS) is widely used for the acquisition of the topography. Nowadays a wide range of ALS sensors is available. One key parameter of ALS systems is the laser wavelength. Next to the geometric information ALS sensors usually record amplitude information for each echo. In practice this radiometric information is hardly used. In order to perform an accurate analysis of these recorded values a radiometric correction that considers all relevant influencing factors is essential.
This contribution focuses on the radiometric calibration, correction, and analysis of ALS data. Furthermore, next to the radiometric correction of monochromatic (single-wavelength) ALS data this study presents multi-wavelength ALS data. After a summary of the basic theory, the radiometric calibration workflow for ALS data sets based on in-situ reference surfaces is presented. Based on individual monochromatic radiometrically corrected reflectance results a calibrated multi-wavelength reflectance image can be generated. It is important to note that this image is not influenced by shadows and from a geometric viewpoint the position of the objects on top of the terrain surface is not altered (true orthophoto).
Within this contribution the practical application and analysis of multi-wavelength radiometric information from ALS data is demonstrated by two different projects both comprising three single-wavelength ALS data acquisitions (532nm, 1064nm, and 1550nm). The practical results show the applicability of calibrating multi-wavelength radiometric imagery from ALS data and provide an insight into the challenges of radiometric processing and exploitation of multi-wavelength ALS data.