Retrieval algorithm for the column CO<sub>2</sub> mixing ratio from pulsed multi-wavelength lidar measurements

Abstract. The retrieval algorithm for CO2 column mixing ratio from measurements of a pulsed multi-wavelength integrated path differential absorption (IPDA) lidar is described. samples the shape 1572.33 nm line at multiple wavelengths. uses least-squares fit between computed layered atmosphere model and that sampled by lidar. In addition to column-average dry-air mole fraction (XCO2), several other parameters are also solved simultaneously fit. These include Doppler shift received laser signal wavelength, product surface reflectivity atmospheric transmission, linear trend in receiver's spectral response. can be used solve average water vapor ratio, which produces secondary wings under humid conditions. linearized about expected XCO2 value, allows use standard fitting method software tools. deviation retrieved obtained covariance matrix averaging kernel provided similarly passive trace-gas measurements. Examples presented using retrieve NASA Goddard airborne Sounder were made constant altitude during spiral-down profile maneuvers.