TROPICAL CYCLONE (TC) INTENSITY FORECAST HAS ONLY HAD MINOR IMPROVEMENTS RELATIVE TO TC TRACK FORECAST OVER THE PAST 20 YEARS. THIS IS BECAUSE TC INTENSITY CHANGE IS INFLUENCED BY MULTIPLE PROCESSES. ONE OF THE PROCESSES THAT HAVE NOT BEEN FULLY UNDERSTOOD IS THE WAY IN WHICH TC RAINBANDS INFLUENCE TC INTENSITY. TC RAINBANDS - WHICH ARE SPIRALING BANDS OF PRECIPITATION SURROUNDING THE TC EYEWALL AND INNER CORE - CONSIST OF CONVECTIVE AND STRATIFORM PRECIPITATION BOTH OF WHICH HAVE DIFFERENT TYPES OF SECONDARY (TRANSVERSE) CIRCULATION. THE CIRCULATION ASSOCIATED WITH RAINBAND CONVECTIVE PRECIPITATION IS THOUGHT TO HAVE A DETRIMENTAL EFFECT ON TC INTENSITY BY ACTING AS A BARRIER THAT PREVENTS HIGH THERMODYNAMIC ENERGY AIR FROM REACHING THE EYEWALL AND INNER CORE AND THUS WEAKENING THE OVERALL TC INTENSITY. THE PROPOSED RESEARCH SEEKS TO CLARIFY THE RELATIONSHIP BETWEEN TC INTENSITY AND THE DISTRIBUTION AND STRENGTH OF RAINBAND CONVECTION. THE APPROACH WOULD INVOLVE UTILIZING A LARGE DATABASE OF TC-CENTERED SATELLITE PASSIVE MICROWAVE OBSERVATIONS ALONG WITH THE CORRESPONDING NASA RAINFALL RETRIEVAL PRODUCTS SUCH AS THE GODDARD PROFILING ALGORITHM (GPROF) AND THE HURRICANE GPROF (HGPROF). BY USING THE RAINFALL RETRIEVAL PRODUCTS AND MICROWAVE BRIGHTNESS TEMPERATURES TO DEDUCE INFORMATION REGARDING THE DISTRIBUTION AND STRENGTH OF TC RAINBAND CONVECTION ITS RELATIONSHIP WITH THE SIMULTANEOUSLY OBSERVED EYEWALL CONVECTION AND OVERALL INTENSITY CAN BE INVESTIGATED. STATISTICAL METHODS WILL BE APPLIED TO INVESTIGATE THIS RELATIONSHIP ON THE LARGE DATASET AVAILABLE. HOWEVER A QUANTIFICATION OF THE UNCERTAINTIES ASSOCIATED WITH A KEY COMPONENT OF THE GPROF AND HGPROF ALGORITHMS THAT WOULD BE UTILIZED IN THIS STUDY - THE CONVECTIVE-STRATIFORM PARTITIONING (CSP) ALGORITHM - IS FIRST NEEDED. A VALIDATION STUDY OF THE GPROF AND HGPROF CSP ALGORITHMS USING SIMULTANEOUS OBSERVATIONS OF MULTIPLE TCS FROM SATELLITE PASSIVE MICROWAVE SENSORS AND GROUNDBASED COASTAL RADARS WILL BE CONDUCTED. THE GPROF AND HGPROF CSP OUTPUTS WILL BE COMPARED TO CSP OUTPUTS FROM GROUND-BASED RADARS AND ANY BIASES AND ERRORS ASSOCIATED WITH THE GPROF AND HGPROF CSP ALGORITHM WILL BE QUANTIFIED. THIS VALIDATION STUDY IS IMPORTANT TO UNDERSTAND HOW THE GPROF/HGPROF CSP ALGORITHMS MAY IMPACT THE OUTCOME OF THE SUBSEQUENT RAINBAND STUDY. THE RESULT OF THIS VALIDATION STUDY IS ALSO EXPECTED TO SERVE AS GUIDANCE FOR FUTURE IMPROVEMENTS TO THE GPROF AND HGPROF CSP ALGORITHMS. THIS RESEARCH WILL DIRECTLY ADVANCE THE OBJECTIVES OF THE EARTH SCIENCE DIVISION OF NASA'S STRATEGIC MISSION DIRECTORATE BY UTILIZING NASA'S ASSETS TO ENHANCE THE KNOWLEDGE REGARDING TC INTENSITY CHANGE IN ORDER TO IMPROVE TC INTENSITY FORECASTING.