BACKGROUND: THE PRIMARY METHOD OF FORECASTING SOLAR WIND-RELATED SPACE WEATHER EVENTS IS VIA THE OPERATIONAL WSA/ENLIL MODEL USED BY NOAA/SWPC USAF/557TH WW AND NASA/CCMC. ONE OF THE LARGEST SOURCES OF UNCERTAINTY IN THIS AND OTHER SOLAR WIND MODELS IS THE ERROR IN THE SOLAR PHOTOSPHERIC MAGNETIC FLUX DENSITY PARTICULARLY IN THE POLAR REGIONS WHERE CORONAL HOLE HIGH-SPEED STREAMS OFTEN ORIGINATE. THE OPERATIONAL VERSIONS OF WSA/ENLIL CURRENTLY USE MAGNETIC FIELD DATA FROM THE NATIONAL SOLAR OBSERVATORY'S GLOBAL OSCILLATIONS NETWORK GROUP (GONG). GONG OPERATIONS ARE NOW FUNDED IN PART BY NOAA AND GONG DATA PROCESSING IS CARRIED OUT ON THE OPERATIONAL NOAA/IDP NETWORK. CENTRAL OBJECTIVE: TO IMPROVE THE ACCURACY OF THE GONG MAGNETIC FIELD INPUT DATA AND HENCE THE ACCURACY OF WSA/ENLIL AMBIENT SOLAR WIND PREDICTIONS. METHODOLOGY: TO IMPROVE THE ACCURACY OF GONG MAGNETIC FIELD DATA WE WILL: 1. APPLY A NEWLY DEVELOPED "END-TO-END" CALIBRATION TO THE GONG DATA PIPELINE AND ARCHIVAL DATA. 2. IMPROVE GONG POLAR FLUX DATA USING NSO/SOLIS NASA SDO/HMI AND HINODE/SOT/SP VECTOR DATA AND PULKOVO OBSERVATORY SYNOPTIC DATA. 3. IMPROVE GONG RADIAL MAGNETIC FLUX MAPS (THE BOUNDARY CONDITION FOR WSA/ENLIL) USING NSO/SOLIS AND NASA/HMI VECTOR FIELD DATA. THE END-TO-END CALIBRATION EFFORT WILL INVOLVE COMPLETION AND APPLICATION OF A DETAILED POLARIMETRIC MODEL OF THE GONG INSTRUMENT AND USE 3D MHD MODELS OF SOLAR MAGNETIC FIELDS WITH NLTE RADIATIVE TRANSFER AS A "REFERENCE MAGNETIC FIELD SOURCE". THE INSTRUMENT RESPONSE TO THESE REFERENCE FIELDS WILL BE COMPARED TO ACTUAL DATA AND A LOOK-UP TABLE WILL BE CREATED TO CORRECT ACTUAL DATA TO THE MODELED RESPONSES. THE POLAR FIELD CORRECTIONS WILL BE CARRIED OUT BY CROSS-CALIBRATION OF LINE-OF-SIGHT DERIVED MEASUREMENTS FROM HIGHER RESOLUTION VECTOR MAGNETIC FIELD DATA AS WELL AS LOWER-RESOLUTION BUT HIGHER SENSITIVITY DATA AND CREATING A LOOK-UP-TABLE BASED CORRECTION TO POLAR REGIONS OF THE GONG INPUT MAPS TO WSA/ENLIL. SIMILARLY THE RADIAL FIELD COMPONENT WILL BE CALIBRATED AGAINST VECTOR DATA TO CREATE A DISK-POSITION AND FLUX-DEPENDENT CORRECTION FACTOR. TO VERIFY AND VALIDATE THESE CHANGES SEVERAL SIGNIFICANT GEOMAGNETIC STORM EVENTS CAUSED BY CORONAL HOLE HIGH-SPEED STREAMS (HSSS) OR CO-ROTATING INTERACTION REGIONS (CIRS) IN THE SOLAR WIND WILL BE SELECTED FOR "RE-FORECASTING" RUNS OF THE WSA/ENLIL MODEL. THESE RUNS WILL BE COMPARED WITH "BASELINE" RUNS USING THE UN-CORRECTED GONG SYNOPTIC MAP INPUTS. FORECASTING ACCURACY WILL BE ASSESSED USING METRICS SUCH AS THE MEAN ABSOLUTE ERROR OF PEAK SOLAR WIND SPEED AND ARRIVAL TIME OF THE EVENT AND POSSIBLY OTHER "SKILL-SCORE" BASED METRICS. PERCEIVED SIGNIFICANCE: THE PROJECT WILL INCREASE THE ACCURACY OF GONG MAGNETIC FIELD MAPS BOTH FOR FUTURE DATA ACQUIRED BY THE NETWORK AND FOR ARCHIVAL DATA USED IN SOLAR RESEARCH AND OPERATIONAL RE-FORECASTING. IT WILL ALSO INCREASE THE ACCURACY OF FUTURE WSA/ ENLIL AMBIENT SOLAR WIND PREDICTIONS LEADING TO BETTER OPERATIONAL FORECASTS OF HSS AND CIR GEOMAGNETIC STORMS AND POSSIBLY ALSO OF CME ARRIVAL TIMES. IN THIS SENSE THE PROJECT IS A CLASSIC "OPERATIONS-TO-RESEARCH" PROGRAM IN WHICH AN OPERATIONAL FORECASTING MODEL IS IMPROVED BY THE APPLICATION OF NEW RESEARCH INTO MODEL INPUT DATA QUALITY.