ABSTRACT: WE PROPOSE TO CHARACTERIZE THE SURFACE AND SUBSURFACE STRUCTURE OF VOLCANIC DEPOSITS ON VENUS MOON AND EARTH USING RADAR REMOTE SENSING DATA IN ORDER TO PROVIDE CONSTRAINTS ON HOW THE VOLCANIC FEATURES WERE FORMED. IN TASK 1 WE PROPOSE TO PERFORM A HEMISPHERE-WIDE STUDY FOCUSED ON IDENTIFICATION AND CHARACTERIZATION OF PYROCLASTIC DEPOSITS ON VENUS USING RADAR POLARIMETRIC DATA. THE MAGNITUDE AND EXTENT OF EXPLOSIVE VOLCANISM ON VENUS IS CURRENTLY UNKNOWN AND UNCONSTRAINED BUT THIS INFORMATION IS IMPORTANT FOR DETERMINING HOW VOLCANISM CONTRIBUTED TO THE CURRENT VENUS CLIMATE. WE WILL REPROCESS PREVIOUSLY ACQUIRED GROUND-BASED VENUS DATA TO PRODUCE TOTAL POWER AND CIRCULAR POLARIZATION RATIO (CPR) IMAGES AT HIGHER RESOLUTION THAN IS CURRENTLY AVAILABLE. WE WILL USE OUR NEWLY REPROCESSED HIGH-RESOLUTION CPR DATA WITH THE PREVIOUSLY DERIVED DEGREE OF LINEAR POLARIZATION DATA AND MAGELLAN CONTEXT IMAGES TO DETERMINE IF THERE ARE SIGNIFICANT DIFFERENCES IN VOLCANIC MORPHOLOGIC TEXTURES BETWEEN SHIELD FIELDS OF DIFFERENT SIZES AND IN PARTICULAR WHETHER ANY OF THE TEXTURES ARE INDICATIVE OF PYROCLASTIC VOLCANISM. THE REPROCESSED DATA WILL BE PUT INTO PDS FORMAT AND PUBLICLY RELEASED. IN TASK 2 WE WILL USE A COMBINATION OF RADAR AND OPTICAL DATA TO DETERMINE THE TEXTURES OF THE DOME DEPOSITS AND INVESTIGATE THE HYPOTHESIS THAT PYROCLASTIC VOLCANISM WAS ASSOCIATED WITH SOME OF THE DOMES. FOR EACH DOME FIELD IN OUR PROPOSED STUDY WE WILL MAP CHANGES IN RADAR PROPERTIES ACROSS THE DOMES CORRELATE WITH OPTICAL IMAGES AND COMPARE THE TYPES OF DEPOSITS (POSSIBLE PYROCLASTICS ROUGH FLOWS SMOOTH FLOWS) THAT OCCUR IN EACH FIELD TO DETERMINE THE RANGE OF VOLCANIC MORPHOLOGIC TEXTURES THAT OCCUR IN EACH LOCATION. IN TASK 3 WE WILL USE AIRBORNE RADAR DATA AND GROUND-PENETRATING RADAR (GPR) FIELD STUDIES TO DETERMINE THE TYPES OF GEOLOGIC SURFACES THAT PRODUCE DIFFERENT RADAR POLARIZATION SCATTERING SIGNATURES. THIS WORK WILL PROVIDE ANALOG EXAMPLES THAT WILL BE USED TO INTERPRET THE DATA IN TASKS 1 AND 2. THE PROPOSED WORK ADDRESSES THE PG&G PROGRAM GOALS OF ANALYSIS AND COMPARATIVE STUDY OF DATA THAT WILL IMPROVE THE UNDERSTANDING OF ...GEOLOGICAL PROCESSES. THIS WORK IS ALSO RELEVANT TO NASA S STRATEGIC GOAL TO ASCERTAIN THE CONTENT ORIGIN AND EVOLUTION OF THE SOLAR SYSTEM. THE PROPOSED POLARIMETRIC CHARACTERIZATION OF VOLCANIC TERRAINS WILL PROVIDE NEW KNOWLEDGE OF THE HISTORY OF VOLCANIC PROCESS ON VENUS AND THE MOON TOPICS THAT ARE CALLED OUT IN THE PLANETARY DECADAL SURVEY INNER PLANETS CHAPTER.