MICROWAVE REMOTE SENSING CAN BE USED TO MEASURE THE SEA SURFACE SALINITY OF THE GLOBAL OCEANS. THIS IS A PROPOSAL TO IMPROVE THE SENSOR S ABILITY TO MEASURE SEA SURFACE SALINITY ACCURATELY. PASSIVE MICROWAVE SENSORS AT 1.4 GHZ MEASURE THE RADIATION EMITTED FROM THE SEA SURFACE. THIS EMISSION IS DIRECTLY RELATED TO THE DIELECTRIC CONSTANT (REFRACTIVE INDEX) OF THE SEAWATER WHICH IN TURN IS RELATED TO ITS SALINITY AND TEMPERATURE. THE RELATIONSHIP BETWEEN THE DIELECTRIC CONSTANT AND THE SEA SURFACE SALINITY AND TEMPERATURE IS CALLED THE MODEL FUNCTION. IF THE TEMPERATURE IS KNOWN THEN THE SALINITY CAN BE FOUND USING THE MODEL FUNCTION. THE GEORGE WASHINGTON UNIVERSITY HAS MADE MEASUREMENTS OF THE DIELECTRIC CONSTANT OF SEAWATER AT SALINITY OF 30 33 35 AND 38 PSU FOR TEMPERATURES VARYING FROM 0 TO 35 C IN 5 STEPS. THIS HAS BEEN DONE BY USING A MICROWAVE CAVITY KEPT AT A CONSTANT AND ACCURATELY KNOWN TEMPERATURE. SEAWATER OF CAREFULLY MEASURED SALINITY IS INSERTED INTO THE CAVITY THROUGH A GLASS TUBE. THE CHANGE IN THE RESONANT FREQUENCY AND WIDTH OF THE RESONANT CURVE DETERMINES THE DIELECTRIC CONSTANT OF THE SEAWATER VERY ACCURATELY. THE PROPOSED WORK WILL INCLUDE MAKING MORE MEASUREMENTS WITH SEAWATER HAVING SALINITY CLOSE TO 35 PSU SINCE MOST SEAWATER HAS SALINITY BETWEEN 34 AND 36 PSU. THIS WILL INCREASE THE ACCURACY OF THE MODEL FUNCTION FOR THE OPEN OCEAN. IT IS ALSO PLANNED TO MEASURE THE SALINITY OF COLD SEAWATER WHERE THE SENSITIVITY TO MICROWAVE EMISSION IS THE WEAKEST. THIS IMPORTANT TEMPERATURE RANGE IS WHERE MELTING ICE AFFECTS THE SEAWATER SALINITY. SINCE GREAT ACCURACY IS REQUIRED FOR COLD SEAWATER MEASUREMENTS IT HAS BEEN PROPOSED TO MEASURE THE RESONANT FREQUENCY OF THE CAVITY AND ITS BANDWIDTH BY A MORE ACCURATE TECHNIQUE FROM WHAT IS PRESENTLY USED. FINALLY SEAWATER MEASUREMENT WILL BE MADE FOR LOW VALUES OF SALINITY WHICH ARE CHARACTERISTIC OF COASTAL REGIONS. THE MEASUREMENTS OF SEA SURFACE SALINITY ARE IMPORTANT FOR AN UNDERSTANDING OF THE ISSUES OF OCEAN CIRCULATION AND THE IMPACT OF CLIMATE CHANGE. THE MEASUREMENTS TO BE MADE WILL PROVIDE THE OCEAN COMMUNITY WITH A MODEL FUNCTION THAT IS ACCURATE FOR OPEN OCEAN CONDITIONS FOR REGIONS OF LOW TEMPERATURE AND FOR AREAS NEAR THE COASTS. IN ORDER TO USE MICROWAVE REMOTE SENSING FOR TRACKING CHANGES IN SALINITY CAUSED BY CLIMATE CHANGE IT IS CRITICAL TO HAVE AN ACCURATE MODEL FUNCTION WHICH IS WHAT THIS PROJECT WILL PROVIDE.