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Workspace Method f_gridFromSensorAMSU

Description

Automatically calculate f_grid to match the sensor.

This method is handy if you are simulating an AMSU-type instrument,
consisting of a few discrete channels. The case that channels touch,
as for MHS, is handled correctly. But the case that channels overlap
is not (yet) handled and results in an error message.

The method calculates f_grid to match the instrument, as given by
the local oscillator frequencies lo_multi, the backend
frequencies f_backend_multi, and the backend channel
responses backend_channel_response_multi.

You have to specify the desired spacing in the keyword *spacing*,
which has a default value of 100 MHz. (The actual value is 0.1e9,
since our unit is Hz.)

The produced grid will not have exactly the requested spacing, but
will not be coarser than requested. The algorithm starts with the band
edges, then adds additional points until the spacing is at least as
fine as requested.

There is a similar method for HIRS-type instruments,
see f_gridFromSensorHIRS.

Authors: Stefan Buehler, Mathias Milz

Synopsis

f_gridFromSensorAMSU(

f_grid, lo_multi, f_backend_multi, backend_channel_response_multi, spacing )

Variables

OUT	f_grid	(Vector)	The frequency grid for monochromatic pencil beam calculations.
IN	lo_multi	(Vector)	Local oscillator frequencies.
IN	f_backend_multi	(ArrayOfVector)	As f_backend but describes an instrument with muliple mixer/receiver chains.
IN	backend_channel_response_multi	(ArrayOfArrayOfGriddedField1)	As backend_channel_response but describes an instrument with muliple mixer/receiver chains.
GIN	spacing	(Numeric, Default: .1e9)	Desired grid spacing in Hz.