Speaker
Description
ALTIUS (Atmospheric Limb Tracker for the Investigation of the Upcoming Stratosphere) is the upcoming stratospheric ozone monitoring mission of ESA’s Earth Watch program. ALTIUS consists of three 2D high resolution imagers: UV (250-355 nm), VIS (440-675 nm) and NIR (600-1040 nm) channels. Each channel is independent of the others and takes snapshots of the atmosphere in limb geometry at requested wavelengths. Stratospheric ozone profiles are the mission’s primary objectives. ALTIUS will measure in three different observation modes to maximize the spatial coverage of the mission: limb scattering on the dayside of the orbit, solar occultation at the terminator and stellar occultations on the nightside of the orbit.
In stellar occultation, the light coming from a star and passing through the atmosphere interacts with irregularities caused by turbulences and gravity waves. Therefore, the signal fluctuates along with the air density on the optical path. This phenomenon is called scintillation and can have a large detrimental effect on the measurements and on the retrieved profiles quality.
This work assesses the influence of scintillation on retrieved ozone profile and the performance of the mitigation strategy used in ALTIUS L2 processing algorithms in stellar occultation mode. Data originating from GOMOS (Global Ozone Monitoring by Occultation of Stars), an atmospheric sensor on board the ENVISAT satellite, is used to perform this study.
