Validation of ozone profiles retrieved from Stratospheric Aerosol and Gas Experiment III limb scatter measurements

Ozone profiles retrieved from Stratospheric Aerosol and Gas Experiment (SAGE III) limb scatter measurements are compared with correlative measurements made by occultation instruments (SAGE II, SAGE III, and HALOE), a limb scatter instrument (Optical Spectrograph and Infrared Imager System (OSIRIS)), a series of ozonesondes and lidars, and a transport model, in order to ascertain the accuracy and precision of the SAGE III instrument in limb scatter mode. The measurement relative accuracy is found to be 5-10% from the tropopause to about 45 km, whereas the relative precision is found to be less than 10% from 20 to 38 km. The height registration, which is inferred directly from radiance data profiles, is found to have a standard deviation ("relative precision") of about 350 m. Measurement repeatability, a measure of absolute precision, which is estimated by multiple measurements over the same geographical area in the tropics on consecutive orbits, is found to be similar to 3%.