Evolution of the Altius instrument

The Altius satellite carries a high-resolution 2D imager, as the photograph shows. It observes ozone from side-on, at Earth's limb or atmospheric boundary. This limb-sounding technique allows ozone to be viewed at different altitudes, thereby providing vertical profiles of different ozone concentrations. The instrument uses three independent spectral imagers that operate in the ultraviolet, visible and near-infrared, achieving global coverage in a three-day revisit cycle.

The sketch shows how the Altius instrument has evolved over time.