THE NORTH AND SOUTH POLAR LAYERED DEPOSITS (PLD) ON MARS HAVE DRASTICALLY DIFFERENT RADAR PROPERTIES. SIGNALS FROM THE MARS RECONNAISSANCE ORBITER (MRO) SHALLOW RADAR (SHARAD) PROPAGATE ENTIRELY THROUGH THE NPLD DETECTING A BASAL REFLECTOR THROUGH A ~2 KM THICK WATER-ICE-RICH DEPOSIT. CONVERSELY SHARAD SIGNALS ARE UNABLE TO TRAVERSE THE ~1 3.5 KM THICK SPLD EVEN THOUGH IT IS ALSO COMPOSED PREDOMINANTLY OF WATER ICE. SOMETHING IS SCATTERING THE SHARAD ECHO CREATING A FOG-LIKE APPEARANCE SUBSEQUENT TO THE SPLD SURFACE RETURN. TYPICALLY SHARAD IMAGES 1.1 1.5 KM INTO THE SPLD THOUGH EVEN IN THIN REGIONS OF THE SPLD (<1.5 KM THICK) THE SHARAD SIGNAL DOES NOT ALWAYS DETECT A BASAL REFLECTOR. ONE TYPE OF SPLD UNIT LOW REFLECTIVITY ZONES (LRZ FORMERLY REFLECTION-FREE ZONES) EXPERIENCES SOME OF THE GREATEST RADAR SIGNAL ATTENUATION AND SOME LRZ ARE IN SOME OF THE THINNEST SPLD REGIONS. AT LOWER FREQUENCIES SIGNALS FROM THE MARS ADVANCED RADAR FOR SUBSURFACE AND IONOSPHERE SOUNDING (MARSIS) ARE ABLE TO DETECT THE BASAL INTERFACE IN MOST REGIONS OF THE SPLD. THUS THE FACTORS CONTROLLING THE PROPAGATION OF RADIO WAVES THROUGH THE SPLD ARE FREQUENCY DEPENDENT. WE PROPOSE A DETAILED ANALYSIS OF THE OBSERVED SCATTERING OF THE SHARAD ECHO IN THE SPLD THAT WILL ENABLE AN ASSESSMENT OF THE PROCESSES RESPONSIBLE (E.G. SURFACE ROUGHNESS MATERIAL COMPOSITION) FOR THE RADAR SIGNAL ATTENUATION. WE WILL INVESTIGATE THE OBSERVED SCATTERING OF THE SHARAD ECHOES THROUGH FOUR TASKS: 1. MAPPING THE SPLD BASAL REFLECTORS USING THE SHARAD AND MARSIS RADAR SOUNDING DATASETS TO ASSESS HOW MUCH OF THE SPLD IS NOT MEASURED BY SHARAD. 2. CALCULATING THE THICKNESS OF LRZ DEPOSITS ACROSS THE SPLD TO DETERMINE THEIR TOTAL VOLUME AND THEIR EFFECT ON THE SCATTERING OF THE SHARAD SIGNAL. 3. LOCATE AND CHARACTERIZE THE DEEPEST SIGNAL PENETRATION IN THE SPLD THROUGH MAPPING THE POWER OF BOTH COHERENT REFLECTORS AND THE SHAPE OF THE FOG SIGNAL WITH DEPTH. 4. MEASURING THE SPLD SURFACE ROUGHNESS USING CTX IMAGE AND CTX DEM DATA. THIS WORK WILL ENHANCE THE SCIENTIFIC RETURN OF THE SHARAD MARSIS AND CTX DATASETS; FEW SUCH STUDIES HAVE BEEN LED BY TEAM MEMBERS WHO ARE NOT MISSION CO-IS. RESULTS FROM THE PROPOSED ANALYSES SUCH AS THE CHARACTERIZATION OF THE SHARAD SIGNAL ATTENUATION WILL QUANTIFY DIFFERENCES BETWEEN THE NPLD AND THE SPLD AND LEAD TO A BETTER UNDERSTANDING OF HOW THE COMPOSITION AND STRUCTURE OF THE PLD CONTROL THEIR EVOLUTION. THESE RESULTS WILL HAVE IMPORTANT IMPLICATIONS FOR THE EXPECTED BEHAVIOR OF RADAR SOUNDERS ON THE NASA EUROPA CLIPPER AND ESA JUICE MISSIONS TO ICY MOONS.