Abstract
The paper describes results of a case study on snow cover area monitoring in the Czech Republic from ENVISAT ASAR WSM data. The investigation is a part of the ESA FLOREO project.
The methodology is based on comparison of two SAR images, a reference, snow-free image, and an image with snow acquired in melting period. A threshold value of -3db is usually advised for discrimination of wet snow.
This threshold underestimates SCA when applied on the whole territory of the CR especially due to heterogeneity of land cover. New approaches for deriving new threshold fitting to the local conditions are investigated; one is based on observations of snow height from meteorological stations and the other uses results of classification of optical data.
The results of processing of 10 pairs of ASAR WSM images showed that further investigation has to be carried out to determinate specific threshold values for snow classification for each land cover class.