PERFOMANCE EVALUATION OF SPECKLE FILTERS FOR PADDY RICE AREAS BASED ON SENTINEL-1 SATELLITE IMAGES

RADAR IMAGES ARE INCREASINGLY USED FOR MONITORING AGRICULTURAL AREAS. FOR IRRIGATED RICE CULTIVATION, DUE TO FACT RADAR IMAGING HAS THE ADVANTAGE OF INTERACTING WITH THE FLOODED FIELDS AND FACILITATING THE IDENTIFICATION OF THESE AREAS. RADAR IMAGES HAVE INHERENT CHARACTERISTIC OF MULTIPLICATIVE NOISE THAT REQUIRES A SPECIAL FILTERING TREATMENT TO IMPROVE CLASSIFICATION RESULTS. THEREFORE, IN THIS STUDY, FIVE DIFFERENT SPECKLE FILTERS WERE EVALUATED FOR THEIR ABILITY TO SUPPRESS NOISE AND PRESERVE IMAGE QUALITY. INITIAL RESULTS SHOWED THAT LEE AND GAMMA MAP FILTERS HAVE GOOD NOISE SUPPRESSION CAPABILITIES AND PRESERVE DETAILS IN HOMOGENEOUS RICE FIELDS.