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Workspace Method f_gridMetMM

Description

Sets f_grid and associated variables match MetMM settings.

The method calculates f_grid to match the specifications of a
met_mm_backend table and method arguments.

You have to specify the desired spacing using the keyword *freq_spacing*.
You can pass a Vector with one element to apply the same spacing to all
channels or pass a spacing value for each channel separately.

Optionally, *freq_number* can be set to specify the mininum number of
frequencies per passband for each channel. The frequencies are placed
equally spaced in each passband. The minimum spacing resulting from
*freq_number* and *freq_spacing* will be used for the calculation. To
explicitly use *freq_spacing* for a channel, *freq_number* can be set
to -1 for this channel.

The number of elements in *freq_number* can either be the number of
channels or 1. If only one element is given, this number is used for
all channels. If *freq_number* is 1 and *freq_spacing* is wider than
the bandwidth of the channel, one frequency is placed in the middle of
each passband.

Frequencies that would be closer than *freq_merge_threshold* in the
generated f_grid are merged together. This value should be left at
the default value. This is only meant to compensate for numerical
inaccuracies in the frequency calculation to merge frequency that are
supposed to be identical.

Authors: Oliver Lemke, Patrick Eriksson

Synopsis

f_gridMetMM(

f_grid, f_backend, channel2fgrid_indexes, channel2fgrid_weights, met_mm_backend, freq_spacing, freq_number, freq_merge_threshold )

Variables

OUT	f_grid	(Vector)	The frequency grid for monochromatic pencil beam calculations.
OUT	f_backend	(Vector)	The frequency position of each backend (spectrometer) channel.
OUT	channel2fgrid_indexes	(ArrayOfArrayOfIndex)	Definition of backend frequency response, link to f_grid.
OUT	channel2fgrid_weights	(ArrayOfVector)	Definition of backend frequency response, weighting of f_grid.
IN	met_mm_backend	(Matrix)	Backend description for meteorological millimeter sensors with passbands.
GIN	freq_spacing	(Vector, Default: [.1e9])	Desired grid spacing in Hz.
GIN	freq_number	(ArrayOfIndex, Default: [-1])	Number of frequencies per passband for each channel.
GIN	freq_merge_threshold	(Numeric, Default: 1)	Merge frequencies that are closer than this value in Hz.