First data from the maestro uv-visible spectrophotometer on board the Canadian science satellite - SCISAT-1

The MAESTRO (Measurement of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation) spectrophotometer was launched on board the ACE (Atmospheric Chemistry Experiment) satellite in August of 2003. This first Canadian science satellite in more than 30 years was designed specifically to investigate the chemistry of the Arctic ozone layer during the late winter and early spring when ozone depletion takes place. The combined instrument complement of an infra-red Fourier Transform Spectrometer (ACE-FTS) and the MAESTRO spectrometer will make a comprehensive, simultaneous measurement set of the chemicals in the stratosphere that control ozone depletion. MAESTRO comprises two diode array, concave, holographic diffraction grating spectrometers covering the spectral regions 270 to 550 nm and 525 to 1000 nm and will makes measurements in both the occultation and backscatter observing modes. Operational products from the instrument include vertical profiles of nitrogen dioxide, ozone and aerosol extinction. Under special conditions a number of other chemicals such as BrO, OclO and formaldehyde may be measurable. This paper will describe the MAESTRO instrument and its data analysis algorithms and will present some preliminary profile results.