# ARTS built-in documentation server

## Workspace Method SurfaceBlackbody

### Description

Blackbody surface, with support for Jacobian calculations. See surfaceBlackbody and SurfaceFastem for complementary information. For this method, surface_props_data must contain these data: "Skin temperature" dsurface_emission_dx is calculated analytically. surface_rmatrix and dsurface_rmatrix_dx are set to 0.

**Authors: **Marc Prange

### Synopsis

### Variables

OUT | surface_los | (Matrix) | Downwelling radiation directions to consider in surface reflection. |

OUT | surface_rmatrix | (Tensor4) | The reflection coefficients for the directions given by surface_los to the direction of interest. |

OUT+IN | dsurface_rmatrix_dx | (ArrayOfTensor4) | The derivative of surface_rmatrix with respect to quantities listed in dsurface_names. |

OUT | surface_emission | (Matrix) | The emission from the surface. |

OUT+IN | dsurface_emission_dx | (ArrayOfMatrix) | The derivative of surface_emission with respect to quantities listed in dsurface_names. |

IN | stokes_dim | (Index) | The dimensionality of the Stokes vector (1-4). |

IN | atmosphere_dim | (Index) | The atmospheric dimensionality (1-3). |

IN | lat_grid | (Vector) | The latitude grid. |

IN | lon_grid | (Vector) | The longitude grid. |

IN | f_grid | (Vector) | The frequency grid for monochromatic pencil beam calculations. |

IN | rtp_pos | (Vector) | Position of a radiative transfer point. |

IN | rtp_los | (Vector) | Line-of-sight at a radiative transfer point. |

IN | surface_props_data | (Tensor3) | Various surface properties. |

IN | surface_props_names | (ArrayOfString) | Name on surface properties found in surface_props_data. |

IN | dsurface_names | (ArrayOfString) | Name of surface retrieval quantities. |

IN | jacobian_do | (Index) | Flag to activate (clear-sky) Jacobian calculations. |