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Workspace Method SurfaceFlatScalarReflectivity

Description

Piecewise linear scalar surface reflectivity.

This method is similar to surfaceFlatScalarReflectivity but the
reflectivities are specified differently and Jacobian calculations
are supported. See SurfaceFastem for general remarks about
methods of SurfaceSomething type.

The method works with scalar reflectivies, i.e. it is assumed that
the reflection at vertical and horizontal polarisation is identical.
The scalar reflectivity is given at a number of frequencies,
specified by the GIN ``f_reflectivities``. The reflectivity at the
first frequency is denoted as "Scalar reflectivity 0" etc. Between
the frequencies in ``f_reflectivities``, the reflectivity is treated
to vary linearly. The reflectivity is assumed to be constant outside
of ``f_reflectivities``, and the end points in ``f_reflectivities`` can be
both inside and outside of the range of f_grid. Setting
``f_reflectivities`` to have a single value, implies that the reflectivity
is constant over f_grid.

For this method, surface_props_data must contain these data:
  "Skin temperature"
  "Scalar reflectivity 0"
  "Scalar reflectivity 1"
  ...
  "Scalar reflectivity N"
where N is the length of ``f_reflectivities``-1.

Authors: Patrick Eriksson

Synopsis

SurfaceFlatScalarReflectivity(

surface_los, surface_rmatrix, dsurface_rmatrix_dx, surface_emission, dsurface_emission_dx, stokes_dim, atmosphere_dim, lat_grid, lon_grid, f_grid, rtp_pos, rtp_los, specular_los, surface_props_data, surface_props_names, dsurface_names, jacobian_do, f_reflectivities )

Variables

OUT	surface_los	(Matrix)	Downwelling radiation directions to consider in surface reflection.
OUT	surface_rmatrix	(Tensor4)	The reflection coefficients for the directions given by surface_los to the direction of interest.
OUT+IN	dsurface_rmatrix_dx	(ArrayOfTensor4)	The derivative of surface_rmatrix with respect to quantities listed in dsurface_names.
OUT	surface_emission	(Matrix)	The emission from the surface.
OUT+IN	dsurface_emission_dx	(ArrayOfMatrix)	The derivative of surface_emission with respect to quantities listed in dsurface_names.
IN	stokes_dim	(Index)	The dimensionality of the Stokes vector (1-4).
IN	atmosphere_dim	(Index)	The atmospheric dimensionality (1-3).
IN	lat_grid	(Vector)	The latitude grid.
IN	lon_grid	(Vector)	The longitude grid.
IN	f_grid	(Vector)	The frequency grid for monochromatic pencil beam calculations.
IN	rtp_pos	(Vector)	Position of a radiative transfer point.
IN	rtp_los	(Vector)	Line-of-sight at a radiative transfer point.
IN	specular_los	(Vector)	The specular direction (for reflection by a flat surface).
IN	surface_props_data	(Tensor3)	Various surface properties.
IN	surface_props_names	(ArrayOfString)	Name on surface properties found in surface_props_data.
IN	dsurface_names	(ArrayOfString)	Name of surface retrieval quantities.
IN	jacobian_do	(Index)	Flag to activate (clear-sky) Jacobian calculations.
GIN	f_reflectivities	(Vector)	Frequency retrieval grid, see above.