THE USE AND AVAILABILITY OF INTERFEROMETRIC SYNTHETIC APERTURE RADAR (INSAR) DATA TO SYNOPTICALLY CHARACTERIZE SURFACE DISPLACEMENTS HAS GROWN TREMENDOUSLY OVER THE PAST FEW YEARS. WHILE ATMOSPHERIC PHASE DELAYS AND ORBITAL ERRORS ARE WELL DOCUMENTED THE EFFECTS OF CHANGING SOIL MOISTURE ON THE INSAR OBSERVATIONS ARE POORLY STUDIED AND THERE ARE CURRENTLY NO MEANS TO CORRECT FOR IT. WE PROPOSE TO USE NASA'S SOIL MOISTURE ACTIVE PASSIVE (SMAP) MISSION AS WELL AS THE NORTH AMERICAN LAND DATA ASSIMILATION SYSTEM (NLDAS) PRODUCTS TO TEST FOR SYSTEMATIC RELATIONS BETWEEN SOIL MOISTURE CHANGES AND INSAR PHASE DIFFERENTIALS. WE WILL ESTIMATE SURFACE MOTION TIME SERIES IN THE SOUTHERN CENTRAL VALLEY ALASKAN PERMAFROST AND THE LAGUNA SALADA USING BOTH C-BAND SENTINEL 1 AND L-BAND ALOS-2 DATA. THE THREE LOCATIONS DEMONSTRATE DYNAMIC AND DIFFERENT SURFACE CONDITIONS IN ORDER TO ILLUMINATE POSSIBLE MECHANISMS FOR SATELLITE BIASES. WE WILL LEVERAGE THE TWO DIFFERENT WAVELENGTH SATELLITES TO ASSESS THE IMPACT SOIL MOISTURE HAS ON EACH. WE WILL LOOK FOR STATISTICALLY SIGNIFICANT TEMPORAL CORRELATIONS BETWEEN SOIL MOISTURE AND THE ERRORS IN OUR INSAR TIME SERIES ESTIMATED FROM COLLOCATED CONTINUOUS GLOBAL POSITIONING SYSTEM (CGPS) GROUND MOTION. USING SMAP AND NLDAS WE WILL FORWARD MODEL SOIL MOISTURE ESTIMATES TO CREATE A DIFFERENTIAL PHASE MODEL OF THE EFFECTS OF CHANGING SOIL MOISTURE WHICH WE CAN THEN REMOVE FROM OUR INSAR TIME SERIES TO RECONCILE DEFORMATION TIME SERIES BETWEEN DIFFERENT WAVELENGTH SATELLITES. THIS PROPOSAL IS AIMED TO DIRECTLY SUPPORT THE UPCOMING NASA ISRO SAR (NISAR) MISSION BY DETERMINING POTENTIAL BIASES IMPORTANT FOR DATA VALIDATION AND SCIENTIFIC INTERPRETATION.