ARTS built-in documentation server

Workspace Method surface_typeInterpTypeMask


Interpolation of surface type mask.

The method determines the surface type(s) at the position of concern
(rtp_pos) from the provided type mask (surface_type_mask).

For the default interpolation method, "nearest", the closest point
in the mask is selected. The surface type is set to the integer part
of the value at the found point, while surface_types_aux is set to
the reminder. For example, if the mask value at closest point is 2.23,
surface_types is set to 2 and surface_type_aux becomes 0.23.
surface_types_weights is set to 1. For this option, all output
arguments have length 1.

With the interpolation set to "linear", the output arguments are
set up to describe a mixture of types. The mask values at the grid cell
corner points are determined, and type and aux values are extracted as
above. The weight associated with each type is calculated as for a
standard bi-linear interpolation. If rte_pos is exactly at the centre
of the grid cell, and three corner points match type 0 and one point
type 1, type 0 and 1 get weight 0.75 and 0.25 respectively.

The altitude in rtp_pos is ignored.

Authors: Patrick Eriksson


surface_typeInterpTypeMask( surface_types, surface_types_aux, surface_types_weights, atmosphere_dim, lat_grid, lat_true, lon_true, rtp_pos, surface_type_mask, method )


OUTsurface_types(ArrayOfIndex)This and associated WSVs describe a mixture of surface types.
OUTsurface_types_aux(Vector)Auxiliary variable to surface_types.
OUTsurface_types_weights(Vector)Auxiliary variable to surface_type.
INatmosphere_dim(Index)The atmospheric dimensionality (1-3).
INlat_grid(Vector)The latitude grid.
INlat_true(Vector)Latitudinal geolocation for 1D and 2D data.
INlon_true(Vector)Longitudinal geolocation for 1D and 2D data.
INrtp_pos(Vector)Position of a radiative transfer point.
INsurface_type_mask(GriddedField2)Classification of the surface using a type coding.
GINmethod(String, Default: "nearest")Interpolation method (see above).