scat_data_singleTmatrix

Workspace.scat_data_singleTmatrix(self: pyarts.arts._Workspace, scat_data_single: Optional[Union[pyarts.arts.WorkspaceVariable, pyarts.arts.SingleScatteringData]] = self.scat_data_single, scat_meta_single: Optional[Union[pyarts.arts.WorkspaceVariable, pyarts.arts.ScatteringMetaData]] = self.scat_meta_single, complex_refr_index: Optional[Union[pyarts.arts.WorkspaceVariable, pyarts.arts.GriddedField3]] = self.complex_refr_index, shape: Union[pyarts.arts.WorkspaceVariable, pyarts.arts.String], diameter_volume_equ: Union[pyarts.arts.WorkspaceVariable, pyarts.arts.Numeric], aspect_ratio: Union[pyarts.arts.WorkspaceVariable, pyarts.arts.Numeric], mass: Optional[Union[pyarts.arts.WorkspaceVariable, pyarts.arts.Numeric]] = std::numeric_limits<Numeric>::quiet_NaN(), ptype: Union[pyarts.arts.WorkspaceVariable, pyarts.arts.String], data_f_grid: Union[pyarts.arts.WorkspaceVariable, pyarts.arts.Vector], data_t_grid: Union[pyarts.arts.WorkspaceVariable, pyarts.arts.Vector], data_za_grid: Union[pyarts.arts.WorkspaceVariable, pyarts.arts.Vector], data_aa_grid: Optional[Union[pyarts.arts.WorkspaceVariable, pyarts.arts.Vector]] = Vector{}, precision: Optional[Union[pyarts.arts.WorkspaceVariable, pyarts.arts.Numeric]] = 0.001, cri_source: Optional[Union[pyarts.arts.WorkspaceVariable, pyarts.arts.String]] = "Set by user, unknown source.", ndgs: Optional[Union[pyarts.arts.WorkspaceVariable, pyarts.arts.Index]] = 2, robust: Optional[Union[pyarts.arts.WorkspaceVariable, pyarts.arts.Index]] = 0, quiet: Optional[Union[pyarts.arts.WorkspaceVariable, pyarts.arts.Index]] = 1, verbosity: Optional[Union[pyarts.arts.WorkspaceVariable, pyarts.arts.Verbosity]] = self.verbosity) → None

A basic interface to Mishchenko’s T-matrix code linked to ARTS.

The method performs a T-matrix calculation for a single scattering element, i.e. a combination of particle shape, size, aspect ratio and orientation.

Particle shape (shape) has two options:

"spheroidal" and "cylindrical"

Particle size (diameter_volume_equ) is given as the equivalent volume sphere diameter. That is, the diameter obtained if all the particle’s material is rearranged into a (solid) sphere.

Particle aspect ratio ar (aspect_ratio) is a numeric value, defined according to Mishchenko’s definition as ratio of horizontal axis a to vertical (rotational) axis b: ar=a/b. That is, oblates have ar>1, prolates ar<1. Perfect spheres (spheroidals with ar=1) can trigger numerical issues. To avoid these, we internally increase their aspect ratio by 1e-6, i.e. turning perfect spheres into very light oblates.

Particle type (ptype) has two options:

"totally_random" and "azimuthally_random"

For totally randomly oriented particles, data_aa_grid is not taken into account (but a Vector type container needs to be passed).

For further information on how aspect ratio and the different shapes and orientations are defined, see the documentation of the T-matrix code found http://www.giss.nasa.gov/staff/mmishchenko/t_matrix.html

Regarding ndgs, we refer to the this comment from the documentation:

“Parameter controlling the number of division points in computing integrals over the particle surface. For compact particles, the recommended value is 2. For highly aspherical particles larger values (3, 4,…) may be necessary to obtain convergence. The code does not check convergence over this parameter. Therefore, control comparisons of results obtained with different NDGS-values are recommended.”

Author(s): Johan Strandgren, Patrick Eriksson

Parameters:

  • scat_data_single (SingleScatteringData, optional) – Structure for the single scattering data. See scat_data_single, defaults to self.scat_data_single [OUT]

  • scat_meta_single (ScatteringMetaData, optional) – Structure for the scattering meta data. See scat_meta_single, defaults to self.scat_meta_single [OUT]

  • complex_refr_index (GriddedField3, optional) – Complex refractive index (n) data. See complex_refr_index, defaults to self.complex_refr_index [IN]

  • shape (String) – Particle shape. Options listed above. [IN]

  • diameter_volume_equ (Numeric) – Particle volume equivalent diameter [m]. See defintion above. [IN]

  • aspect_ratio (Numeric) – Particle aspect ratio. [IN]

  • mass (Numeric, optional) – Particle mass. This information is just included in the meta data, and does not affect the T-matrix calculations. Defaults to NaN [IN]

  • ptype (String) – Particle type/orientation. Options listed above. [IN]

  • data_f_grid (Vector) – Frequency grid of the scattering data to be calculated. [IN]

  • data_t_grid (Vector) – Temperature grid of the scattering data to be calculated. [IN]

  • data_za_grid (Vector) – Zenith angle grid of the scattering data to be calculated. [IN]

  • data_aa_grid (Vector, optional) – Azimuth angle grid of the scattering data to be calculated. Defaults to [] [IN]

  • precision (Numeric, optional) – Accuracy of the computations. Defaults to 0.001 [IN]

  • cri_source (String, optional) – String describing the source of complex_refr_index, for inclusion in meta data. Defaults to "Set by user, unknown source." [IN]

  • ndgs (Index, optional) – See above. So far only applied for random orientation. Defaults to 2 [IN]

  • robust (Index, optional) – Continue even if individual T-matrix calculations fail. Respective scattering element data will be NAN. Defaults to 0 [IN]

  • quiet (Index, optional) – Suppress print output from tmatrix fortran code. Defaults to 1 [IN]

  • verbosity (Verbosity) – ARTS verbosity. See verbosity, defaults to self.verbosity [IN]