The MAX-DOAS is a remote sensing instrument collecting scattered sunlight ...
The MAX-DOAS is a remote sensing instrument collecting scattered sunlight in the UV and visible wavelength range. Applying the differential optical absorption spectroscopy (DOAS) which is based on Lambert-Beer's law it is possible to quantify the amount of trace gases in the atmosphere.
The Bremen MAX-DOAS instrument consists of a grating spectrometer equipped with a cooled CCD detector and a separate telescope unit connected to the main instrument via a quartz fibre bundle. The spectrometer is temperature stabilized to avoid wavelength drifts. Although the CCD used is a 2-dimensional detector, it is operated in full vertical binning for optimal signal to noise. The quartz fibre bundle efficiently depolarizes the incoming light and also provides flexibility for instrument set-up.
To optimize spectral coverage and resolution, the Bremen MAX-DOAS Instrument are equipped with two spectrometers, one for the UV and one for the visible part of the spectrum. The instruments share the telescope unit through a quartz fibre bundle that splits into two ends on the spectrometer side.