Selection of optimized microwindows for atmospheric spectroscopy.

In atmospheric Fourier transform spectroscopy so-called microwindows are usually analyzed for retrieval of trace constituents rather than the spectrum as a whole. These microwindows, which are sets of consecutive spectral grid points, contain one or more prominent transitions of the target species, whereas it is desirable for the signal of interfering species to be minimum. An objective, quantitative method is presented to optimize the microwindow boundaries with respect to random errors, signal of interfering species, other parameter and systematic errors and to select optimum microwindows with respect to their associated retrieval errors. Case studies for N(2)O microwindows are performed for a spaceborne limb emission experiment to assess the dependence of the optimum microwindow width on the retrieval concept.