MCGeneral

A generalised 3D reversed Monte Carlo radiative algorithm, that allows for 2D antenna patterns, surface reflection and arbitrary sensor positions.

The main output variables y and mc_error represent the Stokes vector integrated over the antenna function, and the estimated error in this vector, respectively.

The WSV mc_max_iter describes the maximum number of ‘photons’ used in the simulation (more photons means smaller mc_error). mc_std_err is the desired value of mc_error. mc_max_time is the maximum allowed number of seconds for MCGeneral. The method will terminate once any of the max_iter, std_err, max_time criteria are met. If negative values are given for these parameters then it is ignored.

The WSV mc_min_iter sets the minimum number of photons to apply before the condition set by mc_std_err is considered. Values of mc_min_iter below 100 are not accepted.

Only “1” and “RJBT” are allowed for iy_unit. The value of mc_error follows the selection for iy_unit (both for in- and output.

Author(s): Cory Davis

Parameters:

y (Vector, optional) – The measurement vector. See y, defaults to self.y [OUT]
mc_iteration_count (Index, optional) – Counts the number of iterations (or photons) used in the MC. See mc_iteration_count, defaults to self.mc_iteration_count [OUT]
mc_error (Vector, optional) – Error in simulated y when using a Monte Carlo approach. See mc_error, defaults to self.mc_error [OUT]
mc_points (Tensor3, optional) – Source to emission, position. See mc_points, defaults to self.mc_points [OUT]
mc_source_domain (ArrayOfIndex, optional) – Rough classification of source to emission. See mc_source_domain, defaults to self.mc_source_domain [OUT]
mc_scat_order (ArrayOfIndex, optional) – Number of atmospheric scattering events between emission point and sensor. See mc_scat_order, defaults to self.mc_scat_order [OUT]
mc_antenna (MCAntenna, optional) – Antenna pattern description for dedicated MC calculaions. See mc_antenna, defaults to self.mc_antenna [IN]
f_grid (Vector, optional) – The frequency grid for monochromatic pencil beam calculations. See f_grid, defaults to self.f_grid [IN]
f_index (Index, optional) – Frequency index. See f_index, defaults to self.f_index [IN]
sensor_pos (Matrix, optional) – The sensor position for each measurement block. See sensor_pos, defaults to self.sensor_pos [IN]
sensor_los (Matrix, optional) – The sensor line-of-sight (LOS) for each measurement block. See sensor_los, defaults to self.sensor_los [IN]
stokes_dim (Index, optional) – The dimensionality of the Stokes vector (1-4). See stokes_dim, defaults to self.stokes_dim [IN]
atmosphere_dim (Index, optional) – The atmospheric dimensionality (1-3). See atmosphere_dim, defaults to self.atmosphere_dim [IN]
ppath_step_agenda (Agenda, optional) – Calculation of a propagation path step. See ppath_step_agenda, defaults to self.ppath_step_agenda [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]
iy_space_agenda (Agenda, optional) – Downwelling radiation at the top of the atmosphere. See iy_space_agenda, defaults to self.iy_space_agenda [IN]
surface_rtprop_agenda (Agenda, optional) – Provides radiative properties of the surface. . See surface_rtprop_agenda, defaults to self.surface_rtprop_agenda [IN]
propmat_clearsky_agenda (Agenda, optional) – Calculate the absorption coefficient matrix. See propmat_clearsky_agenda, defaults to self.propmat_clearsky_agenda [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]
refellipsoid (Vector, optional) – Reference ellipsoid. See refellipsoid, defaults to self.refellipsoid [IN]
z_surface (Matrix, optional) – The surface altitude. See z_surface, defaults to self.z_surface [IN]
t_field (Tensor3, optional) – The field of atmospheric temperatures. See t_field, defaults to self.t_field [IN]
vmr_field (Tensor4, optional) – VMR field. See vmr_field, defaults to self.vmr_field [IN]
cloudbox_on (Index, optional) – Flag to activate the cloud box. See cloudbox_on, defaults to self.cloudbox_on [IN]
cloudbox_limits (ArrayOfIndex, optional) – The limits of the cloud box. See cloudbox_limits, defaults to self.cloudbox_limits [IN]
pnd_field (Tensor4, optional) – Particle number density field. See pnd_field, defaults to self.pnd_field [IN]
scat_data (ArrayOfArrayOfSingleScatteringData, optional) – Array of single scattering data. See scat_data, defaults to self.scat_data [IN]
atmfields_checked (Index, optional) – OK-flag for atmospheric grids and (physical) fields. See atmfields_checked, defaults to self.atmfields_checked [IN]
atmgeom_checked (Index, optional) – OK-flag for the geometry of the model atmosphere. See atmgeom_checked, defaults to self.atmgeom_checked [IN]
scat_data_checked (Index, optional) – OK-flag for scat_data. See scat_data_checked, defaults to self.scat_data_checked [IN]
cloudbox_checked (Index, optional) – OK-flag for variables associated with the cloudbox. See cloudbox_checked, defaults to self.cloudbox_checked [IN]
iy_unit (String, optional) – Selection of output unit for radiative transfer methods. See iy_unit, defaults to self.iy_unit [IN]
mc_seed (Index, optional) – The integer seed for the random number generator used by. See mc_seed, defaults to self.mc_seed [IN]
mc_std_err (Numeric, optional) – Target precision (1 std. dev.) for Monte Carlo calculations. See mc_std_err, defaults to self.mc_std_err [IN]
mc_max_time (Index, optional) – The maximum time allowed for Monte Carlo calculations. See mc_max_time, defaults to self.mc_max_time [IN]
mc_max_iter (Index, optional) – The maximum number of iterations allowed for Monte Carlo. See mc_max_iter, defaults to self.mc_max_iter [IN]
mc_min_iter (Index, optional) – The minimum number of iterations allowed for Monte Carlo. See mc_min_iter, defaults to self.mc_min_iter [IN]
mc_taustep_limit (Numeric, optional) – Defines an upper step length in terms of optical thickness for Monte Carlo calculations. See mc_taustep_limit, defaults to self.mc_taustep_limit [IN]
l_mc_scat_order (Index, optional) – The length to be given to mc_scat_order. Note that scattering orders equal and above this value will not be counted. Defaults to 11 [IN]
t_interp_order (Index, optional) – Interpolation order of temperature for scattering data (so far only applied in phase matrix, not in extinction and absorption. Defaults to 1 [IN]
verbosity (Verbosity) – ARTS verbosity. See verbosity, defaults to self.verbosity [IN]