Ozone Dynamics Ultraviolet Spectrometer (ODUS) on board GCOM-A1

The ODUS is a UV-Visible spectrometer designed to monitor the global total ozone field from a Japanese satellite named GCOM (Global Change Observation Mission) A1. This instrument measures backscattered solar UV from the Earth´s atmosphere and surface same as TOMS and GOME type instruments. It adopts Fastie-Ebert type optics (F/5.0, f=250 mm) with one dimension CMOS type silicon photo diode array detector. The optical configuration of ODUS is much like the TOMS but extending spectral coverage of 306 nm to 420 nm and using a newly developed, having high quantum yield, array detector with 230 bands. The spectral resolution is about 0.5 nm. Its instrumental field of view is 1.6 deg×1.6deg, 20 km×20 km at nadir view. The main objective of ODUS is to map the total ozone field with high accuracy in one day. Other objectives are to monitor the sulfur dioxide (SO₂) of volcanic origin and of also polluted urban areas. Minor constituents relating to ozone chemistry such as nitrogen dioxide (NO₂) under polluted conditions, BrO, and OClO are target molecules to be measurable