A Novel Approach for the Radiometric Correction of Airborne Hyperspectral Image Data

Hyperspectral imaging is increasingly used in various environmental measurement applications. Airborne hyperspectral sensors enables ground sampling distances (GSD) below 1 meter with high spectral resolution. In order to utilize this data in quantitative remote sensing applications, an accurate radiometric correction of the imagery has to be performed. In this article we present a radiometric correction method for airborne hyperspectral imagery based on the permanent test field and the ATCOR-4 software. Two campaigns were carried out with AisaEAGLE II hyperspectral sensor in Finland, on summer 2011, one over the Sjökulla image quality test field and another over the Porvoo agricultural fields. Five different radiometrically corrected reflectance images were processed from each image. These images present situations with and without field reference measurements and with and without vicarious in-flight radiometric calibration of the sensor. The data analysis was based on field reflectance measurements of several reference reflectance targets (gravels, tarpaulins, wheat and oilseed rape fields). The usability of the vicarious calibration performed over the Sjökulla test field was tested with the Porvoo image lines. The tested processing versions provided up to 10 % reflectance accuracy without any ground reference and reflectance accuracy up to 5 % with vicarious in-flight calibration of the sensor. The results showed the importance of the vicarious radiometric calibration of the sensor in operational conditions, and that the radiometric correction of airborne hyperspectral images is possible in efficient way.