iyClearsky

Standard method for radiative transfer calculations with emission and a direct (solar) source . Designed to be part of iy_main_agenda. That is, only valid outside the cloudbox (no scattering). For details se the user guide.

The possible choices for iy_unit are

"1": No conversion, i.e. [W/(m^2 Hz sr)] (radiance per frequency unit).
"RJBT": Conversion to Rayleigh-Jean brightness temperature.
"PlanckBT": Conversion to Planck brightness temperature.
"W/(m^2 m sr)": Conversion to [W/(m^2 m sr)] (radiance per wavelength unit).
"W/(m^2 m-1 sr)": Conversion to [W/(m^2 m-1 sr)] (radiance per wavenumber unit).

Expressions applied and considerations for the unit conversion of radiances are discussed in Sec. 5.7 of the ARTS-2.0 article.

iy_unit is only applied if iy_agenda_call1 is 1. This means that no unit ocnversion is applied for internal iterative calls.

Recognised choices for rt_integration_option are:

"first order": A first order integration is applied.
"second order": A second order integration is applied.
"default": Another way to select the first order option.

Some auxiliary radiative transfer quantities can be obtained. Auxiliary quantities are selected by iy_aux_vars and returned by iy_aux. Valid choices for auxiliary data are:

"Radiative background":
Index value flagging the radiative background. The following coding is used: 0=space, 1=surface and 2=cloudbox.
"Optical depth":
Scalar optical depth between the observation point and the end of the present propagation path. Calculated based on the (1,1)-element of the transmittance matrix (1-based indexing), i.e. only fully valid for scalar RT.
"Direct radiation":
Stokes vector of direct radiation. It dimensions are number of frequencies and stokes_dim. If no sun is present in the line of sight, it is zero.
"Radiation Background":
Stokes vector of the radiation at start of the propagation path. It dimensions are number of frequencies and stokes_dim.

If nothing else is stated, only the first column of iy_aux is filled, i.e. the column matching Stokes element I, while remaing columns are are filled with zeros.

Important

No jacobian calculation is supported when suns or gas scattering is included! This will be implemented in a future version.

Author(s): Patrick Eriksson, Richard Larsson, Oliver Lemke, Manfred Brath

Parameters:

iy (Matrix, optional) – Monochromatic pencil beam radiance spectrum. See iy, defaults to self.iy [OUT]
iy_aux (ArrayOfMatrix, optional) – Data auxiliary to iy. See iy_aux, defaults to self.iy_aux [OUT]
diy_dx (ArrayOfTensor3, optional) – Derivative of iy with respect to retrieval quantities. See diy_dx, defaults to self.diy_dx [INOUT]
ppvar_p (Vector, optional) – Pressure along the propagation path. See ppvar_p, defaults to self.ppvar_p [OUT]
ppvar_t (Vector, optional) – Temperature along the propagation path. See ppvar_t, defaults to self.ppvar_t [OUT]
ppvar_nlte (EnergyLevelMap, optional) – Non-LTE temperatures/ratios along the propagation path. See ppvar_nlte, defaults to self.ppvar_nlte [OUT]
ppvar_vmr (Matrix, optional) – VMR values along the propagation path. See ppvar_vmr, defaults to self.ppvar_vmr [OUT]
ppvar_wind (Matrix, optional) – Winds along the propagation path. See ppvar_wind, defaults to self.ppvar_wind [OUT]
ppvar_mag (Matrix, optional) – Magnetic field along the propagation path. See ppvar_mag, defaults to self.ppvar_mag [OUT]
ppvar_f (Matrix, optional) – Doppler adjusted frequencies along the propagation path. See ppvar_f, defaults to self.ppvar_f [OUT]
ppvar_iy (Tensor3, optional) – iy-values along the propagation path. See ppvar_iy, defaults to self.ppvar_iy [OUT]
ppvar_trans_cumulat (Tensor4, optional) – The transmittance between the sensor and each point of the propagation path. See ppvar_trans_cumulat, defaults to self.ppvar_trans_cumulat [OUT]
ppvar_trans_partial (Tensor4, optional) – The transmittance between the points along the propagation path. See ppvar_trans_partial, defaults to self.ppvar_trans_partial [OUT]
iy_id (Index, optional) – Identification number of iy. See iy_id, defaults to self.iy_id [IN]
stokes_dim (Index, optional) – The dimensionality of the Stokes vector (1-4). See stokes_dim, defaults to self.stokes_dim [IN]
f_grid (Vector, optional) – The frequency grid for monochromatic pencil beam calculations. See f_grid, defaults to self.f_grid [IN]
atmosphere_dim (Index, optional) – The atmospheric dimensionality (1-3). See atmosphere_dim, defaults to self.atmosphere_dim [IN]
p_grid (Vector, optional) – The pressure grid. See p_grid, defaults to self.p_grid [IN]
lat_grid (Vector, optional) – The latitude grid. See lat_grid, defaults to self.lat_grid [IN]
lon_grid (Vector, optional) – The longitude grid. See lon_grid, defaults to self.lon_grid [IN]
z_field (Tensor3, optional) – The field of geometrical altitudes. See z_field, defaults to self.z_field [IN]
t_field (Tensor3, optional) – The field of atmospheric temperatures. See t_field, defaults to self.t_field [IN]
nlte_field (EnergyLevelMap, optional) – The field of NLTE temperatures and/or ratios. See nlte_field, defaults to self.nlte_field [IN]
vmr_field (Tensor4, optional) – VMR field. See vmr_field, defaults to self.vmr_field [IN]
abs_species (ArrayOfArrayOfSpeciesTag, optional) – Tag groups for gas absorption. See abs_species, defaults to self.abs_species [IN]
wind_u_field (Tensor3, optional) – Zonal component of the wind field. See wind_u_field, defaults to self.wind_u_field [IN]
wind_v_field (Tensor3, optional) – Meridional component of the magnetic field. See wind_v_field, defaults to self.wind_v_field [IN]
wind_w_field (Tensor3, optional) – Vertical wind component field. See wind_w_field, defaults to self.wind_w_field [IN]
mag_u_field (Tensor3, optional) – Zonal component of the magnetic field. See mag_u_field, defaults to self.mag_u_field [IN]
mag_v_field (Tensor3, optional) – Meridional component of the magnetic field. See mag_v_field, defaults to self.mag_v_field [IN]
mag_w_field (Tensor3, optional) – Vertical component of the magnetic field. See mag_w_field, defaults to self.mag_w_field [IN]
z_surface (Matrix, optional) – The surface altitude. See z_surface, defaults to self.z_surface [IN]
refellipsoid (Vector, optional) – Reference ellipsoid. See refellipsoid, defaults to self.refellipsoid [IN]
ppath_lmax (Numeric, optional) – Maximum length between points describing propagation paths. See ppath_lmax, defaults to self.ppath_lmax [IN]
ppath_lraytrace (Numeric, optional) – Maximum length of ray tracing steps when determining propagation. See ppath_lraytrace, defaults to self.ppath_lraytrace [IN]
cloudbox_on (Index, optional) – Flag to activate the cloud box. See cloudbox_on, defaults to self.cloudbox_on [IN]
gas_scattering_do (Index, optional) – Flag to activate gas scattering. See gas_scattering_do, defaults to self.gas_scattering_do [IN]
suns_do (Index, optional) – Flag to activate the sun(s). See suns_do, defaults to self.suns_do [IN]
iy_unit (String, optional) – Selection of output unit for radiative transfer methods. See iy_unit, defaults to self.iy_unit [IN]
iy_aux_vars (ArrayOfString, optional) – Selection of quantities for iy_aux and when applicable also y_aux. See iy_aux_vars, defaults to self.iy_aux_vars [IN]
jacobian_do (Index, optional) – Flag to activate (clear-sky) Jacobian calculations. See jacobian_do, defaults to self.jacobian_do [IN]
jacobian_quantities (ArrayOfRetrievalQuantity, optional) – The retrieval quantities in the Jacobian matrix. See jacobian_quantities, defaults to self.jacobian_quantities [IN]
ppath (Ppath, optional) – The propagation path for one line-of-sight. See ppath, defaults to self.ppath [IN]
rte_pos2 (Vector, optional) – A second geographical position to define the geometry for. See rte_pos2, defaults to self.rte_pos2 [IN]
suns (ArrayOfSun, optional) – Array of Sun. See suns, defaults to self.suns [IN]
propmat_clearsky_agenda (Agenda, optional) – Calculate the absorption coefficient matrix. See propmat_clearsky_agenda, defaults to self.propmat_clearsky_agenda [IN]
water_p_eq_agenda (Agenda, optional) – Calculation of the saturation pressure of water. See water_p_eq_agenda, defaults to self.water_p_eq_agenda [IN]
rt_integration_option (String, optional) – Switch between integration approaches for radiative transfer steps. See rt_integration_option, defaults to self.rt_integration_option [IN]
iy_main_agenda (Agenda, optional) – Calculation of a single monochromatic pencil beam spectrum. See iy_main_agenda, defaults to self.iy_main_agenda [IN]
iy_space_agenda (Agenda, optional) – Downwelling radiation at the top of the atmosphere. See iy_space_agenda, defaults to self.iy_space_agenda [IN]
iy_surface_agenda (Agenda, optional) – Upwelling radiation from the surface. See iy_surface_agenda, defaults to self.iy_surface_agenda [IN]
iy_cloudbox_agenda (Agenda, optional) – Intensity at boundary or interior of the cloudbox. See iy_cloudbox_agenda, defaults to self.iy_cloudbox_agenda [IN]
gas_scattering_agenda (Agenda, optional) – Calculation of the gas scattering extinction and phase matrix. See gas_scattering_agenda, defaults to self.gas_scattering_agenda [IN]
ppath_step_agenda (Agenda, optional) – Calculation of a propagation path step. See ppath_step_agenda, defaults to self.ppath_step_agenda [IN]
iy_agenda_call1 (Index, optional) – Flag to handle recursive calls of iy_main_agenda. See iy_agenda_call1, defaults to self.iy_agenda_call1 [IN]
iy_transmittance (Tensor3, optional) – Transmittance to be included in iy. See iy_transmittance, defaults to self.iy_transmittance [IN]
rte_alonglos_v (Numeric, optional) – Velocity along the line-of-sight to consider for a RT calculation. See rte_alonglos_v, defaults to self.rte_alonglos_v [IN]
surface_props_data (Tensor3, optional) – Various surface properties. See surface_props_data, defaults to self.surface_props_data [IN]
verbosity (Verbosity) – ARTS verbosity. See verbosity, defaults to self.verbosity [IN]