WITH THE SUPPORT OF PREVIOUS DSCOVR SCIENCE TEAM WE HAVE PRODUCED AND RELEASED THE EPIC O3SO2AI PRODUCT WHICH CONTAINS TOTAL VERTICAL COLUMN OZONE (O3) SULFUR DIOXIDE (SO2) SCENE REFLECTIVITY AND AEROSOL INDEX (AI) USING THE DIRECT VERTICAL COLUMN FITTING (DVCF) ALGORITHM DEVELOPED FOR AURA OMI AND SNPP OMPS-NM. IN MAKING THE O3SO2AI PRODUCT WE HAVE DEVELOPED AND IMPLEMENTED EFFECTIVE SOFT CALIBRATION TECHNIQUE TO MAINTAIN THE ACCURACY AND CONSISTENCY OF THE EPIC ULTRAVIOLET (UV) RADIANCEMEASUREMENTS. WE HAVE ALSO DEVELOPED A SPATIAL OPTIMAL ESTIMATION (SOE) SCHEME FOR SIMULTANEOUS OZONE AND REFLECTIVITY RETRIEVAL FROM MULTIPLE INSTANTANEOUS FIELD OF VIEWS (IFOVS) OF EPIC. THE SOE SCHEME GREATLY IMPROVES THE PRECISION OF OZONE MEASUREMENTS BY EFFECTIVELY REDUCE THE OZONE ARTIFACTS CAUSED BY THE BAND-TO-BAND MISREGISTRATION RESULTED FROM THE DIFFERENCES IN OBSERVATION TIME AMONG THE EPIC UV BANDS. THE ADVANCED DVCF ALGORITHM TOGETHER WITH SOE SCHEME AND SOFT CALIBRATION PROVIDES THE BEST ESTIMATE OF TOTAL O3. VOLCANIC SO2 AND OTHER GEOPHYSICAL QUANTITIES FROM EPIC. COMPARISONS OF O3 SHOW EXCELLENT AGREEMENT BETWEEN EPIC AND MERRA-2 AND THE ACCURACY OF TOTAL O3 IS BETTER THAN 2% FOR THE FULL EPIC RECORD. WE PROPOSE TO CONTINUE PARTICIPATION IN THE DSCOVR SCIENCE TEAM TO MAINTAIN IMPROVE AND VALIDATE THE EPIC O3SO2AI PRODUCT. SPECIFICALLY WE PROPOSE TO CONTINUE APPLICATION OF SOFT CALIBRATION TO REDUCE THE EFFECT OF INSTRUMENT DEGRADATION AND MAINTAIN CALIBRATION CONSISTENCY OVER THE LIFESPAN OF EPIC. WE WILL FURTHER IMPROVE THE PHYSICS IMPLEMENTATION IN THE DVCF ALGORITHM ESPECIALLY THE TREATMENT OF CLOUD AND AEROSOL WITH AN OBJECTIVE TO ACHIEVE HIGHER PRECISION AND ACCURACY OF O3 AND SO2 MEASUREMENTS FROM EPIC. WE WILL VALIDATE THE EPIC O3 AND SO2 MEASUREMENTS THROUGH COMPARISONS WITH CORRELATIVE DATA INCLUDING PRODUCTS FROM OTHER SATELLITE MISSIONS AND GROUND-BASED MEASUREMENTS.