Global Ozone Monitoring by Occultation of Stars (GOMOS) instrument on ENVISAT: requirements, design, and development status

GOMOS is a medium resolution spectrometer designed to measure the concentrations of, and monitor the trends in stratospheric ozone with very high accuracy and to observe other atmospheric trace gases. Using the star occultation technique, GOMOS combines the features of self-calibration, high vertical resolution and good global coverage. Due to its high sensitivity down to 250 nm, which is one of its main design drivers, GOMOS can measure ozone profiles from 15 km to 90 km. Accessible altitude ranges, accuracies and global coverage are optimum on the night side. In addition, it can measure high accuracy temperature profiles, which are of interest for understanding the vertical exchange of energy in the Earth’s atmosphere. The main mission, the instrument and the equipment requirements and performances are presented. The technologically most challenging components and equipments are presented. The GOMOS instrument development has been completed and the flight model delivered and integrated on the ENVISAT spacecraft. The launch took place on March, 1st 2002.