ppathFixedLstep

Workspace.ppathFixedLstep(self: pyarts.arts._Workspace, ppath: pyarts.arts.WorkspaceVariable | pyarts.arts.Ppath | None = self.ppath, atmfields_checked: pyarts.arts.WorkspaceVariable | pyarts.arts.Index | None = self.atmfields_checked, atmgeom_checked: pyarts.arts.WorkspaceVariable | pyarts.arts.Index | None = self.atmgeom_checked, atmosphere_dim: pyarts.arts.WorkspaceVariable | pyarts.arts.Index | None = self.atmosphere_dim, lat_grid: pyarts.arts.WorkspaceVariable | pyarts.arts.Vector | None = self.lat_grid, lon_grid: pyarts.arts.WorkspaceVariable | pyarts.arts.Vector | None = self.lon_grid, z_field: pyarts.arts.WorkspaceVariable | pyarts.arts.Tensor3 | None = self.z_field, refellipsoid: pyarts.arts.WorkspaceVariable | pyarts.arts.Vector | None = self.refellipsoid, z_surface: pyarts.arts.WorkspaceVariable | pyarts.arts.Matrix | None = self.z_surface, cloudbox_on: pyarts.arts.WorkspaceVariable | pyarts.arts.Index | None = self.cloudbox_on, rte_pos: pyarts.arts.WorkspaceVariable | pyarts.arts.Vector | None = self.rte_pos, rte_los: pyarts.arts.WorkspaceVariable | pyarts.arts.Vector | None = self.rte_los, ppath_lmax: pyarts.arts.WorkspaceVariable | pyarts.arts.Numeric | None = self.ppath_lmax, za_scale: pyarts.arts.WorkspaceVariable | pyarts.arts.Index | None = 0, z_coarse: pyarts.arts.WorkspaceVariable | pyarts.arts.Numeric | None = -1, l_coarse: pyarts.arts.WorkspaceVariable | pyarts.arts.Numeric | None = 1e3, verbosity: pyarts.arts.WorkspaceVariable | pyarts.arts.Verbosity | None = self.verbosity) → None

Full propagation path calculation with fixed step length.

Restrictions:

  1. An active cloudbox is not handled (causes an error).

  2. Observations of limb sounding type not handled. That is, zenith angles between 90 and about 120 deg will cause an error.

  3. Unsuitable for downward observation from within the atmosphere.

The method determines the lowest point of the propagation path and applies a fixed step length from that point. This point can be the surface intersection or the sensor position depending on observation geometry.

There is no adjustment at the high altitude end, neither to the top of the atmosphere altitude nor the sensor’s altitude.

Default is to apply a step length of ppath_lmax everywhere. By setting za_scale to 1, the step length is scaled with zenith angle and the steps are rather constant in altitude spacing.

With z_coarse and l_coarse you can introduce another step length at higher altitudes. If z_coarse is > 0, then l_coarse is applied above z_coarse, instead of ppath_lmax. za_scale is considered also for l_coarse.

Author(s): Patrick Eriksson

Parameters:

  • ppath (Ppath, optional) – The propagation path for one line-of-sight. See ppath, defaults to self.ppath [OUT]

  • 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]

  • atmosphere_dim (Index, optional) – The atmospheric dimensionality (1-3). See atmosphere_dim, defaults to self.atmosphere_dim [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]

  • cloudbox_on (Index, optional) – Flag to activate the cloud box. See cloudbox_on, defaults to self.cloudbox_on [IN]

  • rte_pos (Vector, optional) – A geographical position for starting radiative transfer calculations. See rte_pos, defaults to self.rte_pos [IN]

  • rte_los (Vector, optional) – A line-of-sight for (complete) radiative transfer calculations. See rte_los, defaults to self.rte_los [IN]

  • ppath_lmax (Numeric, optional) – Maximum length between points describing propagation paths. See ppath_lmax, defaults to self.ppath_lmax [IN]

  • za_scale (Index, optional) – Scale step length with 1/abs(cos(za)). Defaults to 0 [IN]

  • z_coarse (Numeric, optional) – Altitude for switching to coarse step length. Defaults to -1 [IN]

  • l_coarse (Numeric, optional) – Coarse step length. Defaults to 1e3 [IN]

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