title: Absolute radiometric calibration of Als intensity data: effects on accuracy and target classification.
abstract: Radiometric calibration of airborne laser scanning (ALS) intensity data aims at retrieving a value related to the target scattering properties, which is independent on the instrument or flight parameters. The aim of a calibration procedure is also to be able to compare results from different flights and instruments, but practical applications are sparsely available, and the performance of calibration methods for this purpose needs to be further assessed. We have studied the radiometric calibration with data from three separate flights and two different instruments using external calibration targets. We find that the intensity data from different flights and instruments can be compared to each other only after a radiometric calibration process using separate calibration targets carefully selected for each flight. The calibration is also necessary for target classification purposes, such as separating vegetation from sand using intensity data from different flights. The classification results are meaningful only for calibrated intensity data.
authors.affiliation: Department of Remote Sensing and Photogrammetry, Finnish Geodetic Institute, Geodeetinrinne 2, P.O. Box 15, 02431 Masala, Finland. sanna.kaasalainen@fgi.fi
authors.forename: Sanna
authors.initials: S
authors.lastname: Kaasalainen
authors.forename: Ulla
authors.initials: U
authors.lastname: Pyysalo
authors.forename: Anssi
authors.initials: A
authors.lastname: Krooks
authors.forename: Ants
authors.initials: A
authors.lastname: Vain
authors.forename: Antero
authors.initials: A
authors.lastname: Kukko
authors.forename: Juha
authors.initials: J
authors.lastname: Hyyppä
authors.forename: Mikko
authors.initials: M
authors.lastname: Kaasalainen