Spectrometer sunlight and moonlight measurements of Ozone (O3), Nitrogen Dioxide (NO2), Chlorine Dioxide (OClO) and Bromine Oxide (BrO) from Arrival Heights

Direct measurements of the instrumental line shape (ILS) with a nitrous oxide calibration cell before and after alignment adjustments are carried out three times a year and on a monthly basis to allow a much better characterisation of the ILS than simply assuming the theoretical ILS. This project is a collaboration with the University of Heidleberg. The technique is sometimes refered to as MAX-DOAS Multple-Axis Dual Optical Absorption Spectrometry.

The spectrometer and control system was built in Heidelberg with the sun tracker built to a Lauder design. The instrument was originally configured with a photodiode array (DA) detector, but was reconfigured with a CCD detector and different software in 2007.