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Workspace Method sensor_responseMetMM
Description
Sensor setup for meteorological millimeter instruments.
This method is handy if you are simulating a passband-type instrument,
consisting of a few discrete channels.
For flexibility, the Met-MM system is seperated in two calculation
steps. To fully use the system, create f_grid (and some associated
variables) by f_gridMetMM before calling this method. However, it is
possible to use this method with any f_grid, as long as matching
f_backend, channel2fgrid_indexes and channel2fgrid_weights
are provided.
Each scan sequence is treated as a measurement block. sensor_pos is
set in the standard way. The number of rows in sensor_pos determines the
number of scan sequences that will be simulated. On the other hand,
sensor_los is handled in a special way. All zenith angles must be set
to 180 deg. For 3D, the given azimuth angles are taken as the direction
of scanning, where the azimuth angle is defined with respect to North
in standard manner. For example, if the scanning happens to move from
SW to NE, the azimuth angle should be set to 45 deg. The angles of the
scanning sequence are taken from antenna_dlos. This WSV is here only
allowed to have a single column, holding relative zenith angles. For
3D, the azimuth angles in antenna_dlos are hard-coded to zero. As
zenith angles in sensor_los are locked to 180 deg, antenna_dlos
effectively holds the nadir angles. These angles can be both positive or
negative, where the recommended choice is to operate with negative
to end up with final zenith angles between 0 and 180 deg.
The method does not support 2D atmospheres (across-track scanning is
inconsistent with 2D). For simpler switching between 1D and 3D,
the argument *mirror_dza* is at hand. It can only be used for 3D.
If set to true, the zenith angles in antenna_dlos are mapped
to also cover the other side of the swath and the simulations will
cover both sides of the swath.
Authors: Oliver Lemke, Patrick Eriksson
Synopsis
sensor_responseMetMM( | antenna_dim, mblock_dlos_grid, sensor_response, sensor_response_f, sensor_response_pol, sensor_response_dlos, sensor_response_f_grid, sensor_response_pol_grid, sensor_response_dlos_grid, sensor_norm, atmosphere_dim, stokes_dim, f_grid, f_backend, channel2fgrid_indexes, channel2fgrid_weights, iy_unit, antenna_dlos, met_mm_polarisation, met_mm_antenna, use_antenna, mirror_dza ) |
Variables