ARTS is a radiative transfer model for the millimeter and sub-millimeter spectral range. There are a number of models mostly developed explicitly for the different sensors. The basic principle for the development of ARTS is to provide a code that can be applied for many different applications concerning radiative transfer calculations in the microwave region. For this reason much emphasis has been placed on modularity, extendibility, and generality.
ARTS is a community effort. The core development is done by Universität Hamburg and Chalmers University.
Key Features
- implemented in C++
- modular design
- spherical geometry (1D, 2D, or 3D)
- state of the art absorption models: line-by-line calculations based on HITRAN or other catalogs plus various continua
- two different methods to handle scattering
- Monte Carlo
- Discrete Ordinate Iterative solution method (DOIT)
- absorption lookup table approach for better efficiency
- analytical or semi-analytical Jacobians for a large set of state parameters
- suitable for microwave to thermal IR calculations
- 1 to 4 Stokes components (allows polarized RT calculations)
- all viewing geometries: up, limb, nadir, from inside or outside the atmosphere)
- large flexibility in setup (governed by controlfiles)
- XML and NetCDF file format support for data import and export
(Current) Limitations
- not suitable for shortwave calculations (near IR-UV)
- no collimated beam source (solar source)
- no absorption models for UV/VIS
- single scattering properties have to be pre-calculated externally
- no sophisticated surface models
