Microwave And Optical Techniques For Forest Monitoring: The Black Forest Experiment

Abstract

During the Summer 1991 the multisensor campaign MAC-Europe 91 took place over several test sites in Europe. The Institute for Remote Sensing Application of the Joint Research Centre selected the Black Forest area in South Germany for the experiment. Intensive ground truth mapping and information provided by the German Forestry department complemented the remote sensed data sets over the site. The information content of the electromagnetic wave reflected by the vegetation layer is exploited by using a large class of sensors (AVIRIS, TMS, GER 11, AIRSAR) operating from the visible to the microwave regions. In this paper we present preliminary results achieved by computing classical indices derived from optical (NDVI,MSI,GEMI, Red edge ) and radar (backscattered power,polarization indices) data acquired on the same test site.The radiometrically calibrated optical data were first corrected for atmospheric effects, using an empirical method for the GER I1 data and the Atmospheric Removal Procedure for the AVIRIS data. The radar images were calibrated and georeferenced. The various indices were then produced. According to literature, these indices are sensitive to a variety of canopy characteristics such as biomass (leafy and woody), water content and tree growth stage (structure, damage). The retrieved indices were correlated with the available ground information on these variables and their performance was assessed for this particular test site.