PROPER INTERPRETATION OF SPECTRAL OBSERVATIONS FROM THE ORBITING CARBON OBSERVATORY-2 (OCO-2) REQUIRES STATE-OF-THE-ART KNOWLEDGE OF THE CARBON DIOXIDE AND OXYGEN ABSORPTION COEFFICIENTS. ONGOING EFFORTS HAVE PUSHED THE MODEL TO THE LIMITS OF FOURIER TRANSFORM SPECTROSCOPY AND COUPLED LASER BASED DATA INTO THE OXYGEN MODEL WHILE SIMULTANEOUSLY DEVELOPING TEMPERATURE CONTROLLABLE LASER SPECTROMETERS AT CALTECH AND NIST. DESPITE PROGRESS ON ALL FRONTS FURTHER IMPROVEMENTS ARE REQUIRED MOLECULAR FOR CO2 (AT 2.1 AND 1.6 MICRONS) AND O2 (AT 0.76 MICRONS). THIS TEAM INCLUDES PARTNERS WITH EXPERTISE IN CODE DEVELOPMENT OCO-2 L2 DATA GENERATION (ABSCO TABLES) AS WELL AS EXPERTISE WITH VALIDATIONS USING TCCON GOSAT AND OCO-2 DATA. THESE VALIDATION STUDIES INDICATE THAT BAND-TO-BAND INCONSISTENCIES REMAIN IN HIGH AIR-MASS OCO-2 RETRIEVALS DUE TO A VARIETY OF ISSUES THAT INCLUDE KNOWN DEFICIENCIES IN THE SPECTROSCOPIC DATA MODELS. THIS PROPOSAL WILL CONTINUE THE EFFORT TO RESOLVE THESE PROBLEMS PRIMARILY BY IMPROVING SPECTROSCOPIC KNOWLEDGE OF MOLECULAR LINE SHAPES LINE-MIXING AND COLLISION-INDUCED ABSORPTION FOR THE O2 A-BAND BUT ALSO BY ADDING ADDITIONAL HIGH PRECISION CO2 DATA THAT IS TRACEABLE TO STANDARDS TO THE DATA MODEL. TO ACHIEVE THESE GOALS WE SIMULTANEOUSLY USE DATA FROM THREE DIFFERENT TYPES OF SPECTROMETERS TO RETRIEVE THE SPECTROSCOPIC PARAMETERS WITH CUSTOMIZED MULTI-SPECTRAL FITTING SOFTWARE. THIS COLLABORATIVE EFFORT HAS THE ADVANTAGE OF THREE EXISTING LABORATORY DATA SOURCES: I) FOURIER-TRANSFORM SPECTRA (FTS) AT DIFFERENT TEMPERATURES (140 - 296 K) AND SPECTRA AT ROOM TEMPERATURE FROM II) CAVITY RINGDOWN (CRDS) AND III) PHOTO ACOUSTIC (PAS) AT HIGH PRESSURES. THE CRDS AND PAS DATA SETS ARE 'BACKGROUND FREE' AND PROVIDE THE CAPABILITY TO EXTRACT NON-RESONANT (CONTINUUM INDUCED ABSORPTION OR CIA) ABSORPTION FROM HIGH DENSITY GASES. THUS THIS IS A FOCUSED EFFORT TO FORGE A COMMON ANALYTIC SOLUTION THAT TAKES ADVANTAGE OF THE MOST FAVORABLE ASPECTS FOR EACH TECHNIQUE. THE KEY OBJECTIVE IS TO OBTAIN THE BEST LINE POSITIONS INTENSITIES PRESSURE-BROADENING COEFFICIENTS (WIDTHS AND PRESSURE-INDUCED SHIFTS) AND THEIR TEMPERATURE DEPENDENCES THAT ARE INTERNALLY CONSISTENT. THIS WILL BE ACHIEVED USING A MULTI-SPECTRAL FITTING PROGRAM TO SIMULTANEOUSLY RETRIEVE ALL THESE PARAMETERS USING THE FTS CRDS AND PAS DATA AT THE SAME TIME. THE MULTISPECTRUM FITTING CODE ALSO CONTAINS THE NECESSARY ALGORITHMS TO GENERATE THE ABSORPTION COEFFICIENT (ABSCO) TABLES FOR USE IN THE OCO-2 ALGORITHM SUCH THAT IDENTICAL PHYSICS CODE AND ASSUMPTIONS ARE USED IN BOTH PROCESSES. THE LABFIT PROGRAM CAN FIT A VARIETY OF LINESHAPE FUNCTION INCLUDING THE HARTMAN-TRAN PROFILE THAT HAS RECENTLY BECOME THE BASIS FOR THE HITRAN DATABASE. MUCH OF THE EFFORTS OF THIS TEAM HAVE BEEN INCORPORATED (AND MAY CONTINUE TO BE INCORPORATED) INTO THE HITRAN DATABASE FOR USE BY THE SCIENTIFIC COMMUNITY.