<title>Global ozone monitoring by occultation of stars</title>

Abstract

We analyzed a set of GOMOS bright limb measurements with solar zenith angles less than 80 o , and within 150 km of SAGE II measurements. In order to perform any species retrieval, GOMOS measurements were first corrected for stray light contamination. Ozone profile retrievals were performed using GOMOS data in the OMPS limb profiler algorithm in order to evaluate code functionality under different atmospheric conditions, assess the accuracy of the pointing algorithm, and identify potential improvements.The OMPS algorithm performs a simultaneous optimal estimation inversion of both Hartley-Huggins and Chappuis band radiances. GOMOS ozone retrievals are restricted to 25-53 km because of signal saturation and residual stray light. The retrieved ozone profiles agree with collocated SAGE II measurements on average to within 10%, and with a standard deviation of 10%. Retrieval results were consistent for both upper and lower GOMOS detector bands.