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Workspace Method iyIndependentBeamApproximation
Description
Samples atmosphere along ppath and make 1D-type RT calculation. The main application of this method should be to apply 1D scattering solvers on 2D or 3D atmospheres. The 1D calculation is set up inside iy_independent_beam_approx_agenda. The method calculates the ppath until reaching the surface or the top-of-the atmosphere. If the sensor is inside the atmosphere the ppath is extended from the sensor vertically to cover the remaining part of the atmosphere. All atmospheric fields are interpolated to the obtain ppath, to form a 1D view of the atmosphere. This 1D atmosphere forms the input to iy_independent_beam_approx_agenda lat_true and lon_true for the 1D view is set to the intersection with the surface of the ppath described above. The function accepts that the input atmosphere is 1D, as well as that there is no active cloudbox. The constructed 1D atmosphere is exported if the GIN *return_atm1d* is set to 1. The default then is to include all atmospheric fields, but vmr_field and pnd_field can be deselected by two of the GIN-s. The order of the fields is specified by the first grid in the structure member grids. If atm_fields_compact is denoted as A, then A.grids{0}{i} gives the name of field with index i. Each book in vmr_field and pnd_field is stored separately. For example, the first book in pnd_field is stored with the name "Scattering element 0".
Authors: Patrick Eriksson
Synopsis
| iyIndependentBeamApproximation( | iy, iy_aux, ppath, diy_dx, atm_fields_compact, iy_id, f_grid, atmosphere_dim, p_grid, lat_grid, lon_grid, lat_true, lon_true, t_field, z_field, vmr_field, nlte_field, wind_u_field, wind_v_field, wind_w_field, mag_u_field, mag_v_field, mag_w_field, cloudbox_on, cloudbox_limits, pnd_field, particle_masses, ppath_agenda, ppath_lmax, ppath_lraytrace, iy_agenda_call1, iy_unit, iy_transmittance, rte_pos, rte_los, rte_pos2, jacobian_do, iy_aux_vars, iy_independent_beam_approx_agenda, return_atm1d, skip_vmr, skip_pnd, return_masses ) |
Variables
| OUT | iy | (Matrix) | Monochromatic pencil beam radiance spectrum. |
| OUT | iy_aux | (ArrayOfMatrix) | Data auxiliary to iy. |
| OUT | ppath | (Ppath) | The propagation path for one line-of-sight. |
| OUT+IN | diy_dx | (ArrayOfTensor3) | Derivative of iy with respect to retrieval quantities. |
| OUT | atm_fields_compact | (GriddedField4) | A compact set of atmospheric fields on a common set of grids. |
| IN | iy_id | (Index) | Identification number of iy. |
| IN | f_grid | (Vector) | The frequency grid for monochromatic pencil beam calculations. |
| IN | atmosphere_dim | (Index) | The atmospheric dimensionality (1-3). |
| IN | p_grid | (Vector) | The pressure grid. |
| IN | lat_grid | (Vector) | The latitude grid. |
| IN | lon_grid | (Vector) | The longitude grid. |
| IN | lat_true | (Vector) | Latitudinal geolocation for 1D and 2D data. |
| IN | lon_true | (Vector) | Longitudinal geolocation for 1D and 2D data. |
| IN | t_field | (Tensor3) | The field of atmospheric temperatures. |
| IN | z_field | (Tensor3) | The field of geometrical altitudes. |
| IN | vmr_field | (Tensor4) | VMR field. |
| IN | nlte_field | (EnergyLevelMap) | The field of NLTE temperatures and/or ratios. |
| IN | wind_u_field | (Tensor3) | Zonal component of the wind field. |
| IN | wind_v_field | (Tensor3) | Meridional component of the magnetic field. |
| IN | wind_w_field | (Tensor3) | Vertical wind component field. |
| IN | mag_u_field | (Tensor3) | Zonal component of the magnetic field. |
| IN | mag_v_field | (Tensor3) | Meridional component of the magnetic field. |
| IN | mag_w_field | (Tensor3) | Vertical component of the magnetic field. |
| IN | cloudbox_on | (Index) | Flag to activate the cloud box. |
| IN | cloudbox_limits | (ArrayOfIndex) | The limits of the cloud box. |
| IN | pnd_field | (Tensor4) | Particle number density field. |
| IN | particle_masses | (Matrix) | The mass of individual particles (or bulks). |
| IN | ppath_agenda | (Agenda) | Agenda calculating complete propagation paths. |
| IN | ppath_lmax | (Numeric) | Maximum length between points describing propagation paths. |
| IN | ppath_lraytrace | (Numeric) | Maximum length of ray tracing steps when determining propagation paths. |
| IN | iy_agenda_call1 | (Index) | Flag to handle recursive calls of iy_main_agenda The agenda iy_main_agenda can be used recursively and this flag is used to tell the methods inside the agenda which is the primary call. |
| IN | iy_unit | (String) | Selection of output unit for radiative transfer methods. |
| IN | iy_transmittance | (Tensor3) | Transmittance to be included in iy. |
| IN | rte_pos | (Vector) | A geographical position for starting radiative transfer calculations. |
| IN | rte_los | (Vector) | A line-of-sight for (complete) radiative transfer calculations. |
| IN | rte_pos2 | (Vector) | A second geographical position to define the geometry for radiative transfer calculations. |
| IN | jacobian_do | (Index) | Flag to activate (clear-sky) Jacobian calculations. |
| IN | iy_aux_vars | (ArrayOfString) | Selection of quantities for iy_aux and when applicable also y_aux. |
| IN | iy_independent_beam_approx_agenda | (Agenda) | Agenda dedicated to iyIndependentBeamApproximation. |
| GIN | return_atm1d | (Index, Default: 0) | Flag to trigger that atm_fields_compact is filled. |
| GIN | skip_vmr | (Index, Default: 0) | Flag to not include vmr data in atm_fields_compact. |
| GIN | skip_pnd | (Index, Default: 0) | Flag to not include pnd data in atm_fields_compact. |
| GIN | return_masses | (Index, Default: 0) | Flag to include particle category masses in atm_fields_compact.Conversion is done by particle_masses. |