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Workspace Method sensor_responseFillFgrid
Polynomial frequency interpolation of spectra.
The sensor response methods treat the spectra to be piece-wise linear
functions. This method is a workaround for making methods handling
the spectra in a more elaborate way: it generates spectra on a more
dense grid by polynomial interpolation. The interpolation is not
done explicitly, it is incorporated into sensor_response.
This method should in general increase the calculation accuracy for
a given f_grid. However, the selection of (original) grid points
becomes more sensitive when using this method. A poor choice of grid
points can result in a decreased accuracy, or generation of negative
radiances. Test calculations indicated that the error easily can
increase with this method close the edge of f_grid, and it could
be wise to make f_grid a bit wider than actually necessary to avoid
The method shall be inserted before the antenna stage. That is, this
method shall normally be called directly after sensor_responseInit.
Between each neighbouring points of f_grid, this method adds
*nfill* grid points. The polynomial order of the interpolation is
Authors: Patrick Eriksson