https://github.com/andrewannex/eradiate

Eradiate: a next-generation radiative transfer model for Earth observation applications

https://github.com/andrewannex/eradiate

Repository

Eradiate: a next-generation radiative transfer model for Earth observation applications

https://github.com/AndrewAnnex/eradiate/blob/main/

![Eradiate logo](docs/fig/eradiate-logo.svg "Eradiate  A new-generation radiative transfer simulation package")

# Eradiate Radiative Transfer Model

[![pypi][pypi-badge]][pypi-url]
[![docs][rtd-badge]][rtd-url]
[![ruff][ruff-badge]][ruff-url]
[![zenodo][zenodo-badge]][zenodo-url]

[pypi-badge]: https://img.shields.io/pypi/v/eradiate?style=flat-square
[pypi-url]: https://pypi.org/project/eradiate/
[rtd-badge]: https://img.shields.io/readthedocs/eradiate?logo=readthedocs&logoColor=white&style=flat-square
[rtd-url]: https://eradiate.readthedocs.io/en/latest/
[ruff-badge]: https://img.shields.io/badge/%E2%9A%A1%EF%B8%8F-ruff-%23171029?style=flat-square
[ruff-url]: https://ruff.rs
[zenodo-badge]: https://img.shields.io/badge/doi-10.5281/zenodo.7224314-blue.svg?style=flat-square
[zenodo-url]: https://zenodo.org/records/7224314

![Development supported by ESA and the European Commission (light mode)](docs/_static/esa_copernicus-logos-light.svg#gh-light-mode-only)

![Development supported by ESA and the European Commission (dark mode)](docs/_static/esa_copernicus-logos-dark.svg#gh-dark-mode-only)

Eradiate is a modern radiative transfer simulation software package for Earth
observation applications. Its main focus is accuracy, and for that purpose, it
uses the Monte Carlo ray tracing method to solve the radiative transfer
equation.

## Detailed list of features


  
Spectral computation

  

  

  Solar reflective spectral region
  
  Eradiate ships spectral data in the solar reflective region (at least from
  280 nm to 2500 nm).
  

  

  

  Line-by-line simulation
  
  These are true monochromatic simulations (as opposed to narrow band
  simulations).
  Eradiate provides
  monochromatic absorption databases covering the [250, 3125] nm interval.
  User-defined absorption databases are also supported (see the
  database format).
  

  

  

  Band simulation
  
  These simulations computes results in spectral bands.
  The correlated k-distribution (CKD) method with configurable
  quadrature rule is used. This method achieves a trade-off between performance
  and accuracy for the simulation of absorption by gases.
  Eradiate provides
  CKD-ready absorption databases
  for the [250, 3125] nm
  interval, with various spectral bin sizes (100 cm, 1 nm, 10 nm).
  User-defined absorption databases are also supported (see the
  database format).
  

  

  

  Polarization
  
  Eradiate optionally supports polarized light simulation. This feature can be
  switched on or off to achieve the best compromise between accuracy and
  performance.
  
  

  
Atmosphere

  

  

  One-dimensional atmospheric profiles
  
  Both standard profiles, e.g. the AFGL (1986) profiles, and customized
  profiles are supported.
  

  

  

  Plane-parallel and spherical-shell geometries
  
  This allows for more accurate results at high illumination and viewing
  angles.
  
  

  
Surface

  

  

  Lambertian, RPV, Ross Thick-Li Sparse and Hapke reflection models
  
  All models can be parametrized against the spectral dimension.
  

  

  

  Detailed surface geometry
  
  Add a discrete canopy model (either disk-based abstract models, or more
  realistic mesh-based models).
  

  

  

  Combine with atmospheric profiles
  
  Your discrete canopy can be integrated within a scene featuring a 1D
  atmosphere model in a fully coupled simulation.
  
  

  
Illumination

  

  

  Directional or finite-size illumination model
  
  Eradiate supports both ideal (Delta angular distribution), and realistic
  (finite angular size) illumination models.
  

  

  

  Many irradiance datasets
  
  Pick your favourite
  or
  bring your own.
  
  

  
Measure

  

  

  Top-of-atmosphere radiance and BRF computation
  
  An ideal model suitable for satellite data simulation.
  

  

  

  Perspective camera sensor
  
  Greatly facilitates scene setup: inspecting the scene is very easy.
  

  

  

  Many instrument spectral response functions
  
  Our SRF data
  is very close to the original data, and we provide advice to
  further clean up the data and find the right balance between accuracy and
  performance.
  
  

  
Monte Carlo ray tracing

  

  

  Mitsuba renderer as radiometric kernel
  
  We leverage the advanced Python API of a cutting-edge C++ rendering system.
  

  

  

  State-of-the-art volumetric path tracing algorithm
  
  Mitsuba ships a null-collision-based volumetric path tracer which performs
  well in many of the cases Eradiate is used for. We also provide a
  special-purpose path tracing algorithm for plane-parallel geometries that can
  perform up to 2 orders of magnitude faster than the null-collision algorithm.
  
  

  
Traceability

  

  

  Documented data and formats
  
  We explain where our data comes from and how users can build their own data
  in a format compatible with Eradiate's input.
  

  

  

  Transparent algorithms
  
  Our algorithms are researched and documented, and their implementation is
  open-source.
  

  

  

  Thorough testing
  
  Eradiate is shipped with a large unit testing suite and benchmarked
  periodically against community-established reference simulation software.
  
  

  
Interface

  

  

  Comprehensive Python interface
  
  Abstractions are derived from computer graphics and Earth observation and
  are designed to feel natural to EO scientists.
  

  

  

  Designed for interactive usage
  
  Jupyter notebooks are now an essential tool in the digital scientific
  workflow.
  

  

  

  Integration with Python scientific ecosystem
  
  The implementation is done using the Scientific Python stack.
  

  

  

  Standard data formats (mostly NetCDF)
  
  Eradiate uses predominantly Xarray data
  structures for I/O.
  
  


## Installation and usage

For build and usage instructions, please refer to the
[documentation](https://eradiate.readthedocs.org).

## Support

Got a question? Please visit our
[discussion forum](https://github.com/eradiate/eradiate/discussions).

## Authors and acknowledgements

Eradiate is developed by a core team consisting of Vincent Leroy,
Sebastian Schunke, Nicolas Misk and Yves Govaerts.

Eradiate uses the
[Mitsuba 3 renderer](https://github.com/mitsuba-renderer/mitsuba3), developed by
the [Realistic Graphics Lab](https://rgl.epfl.ch/),
taking advantage of its Python interface and proven architecture, and extends it
with components implementing numerical methods and models used in radiative
transfer for Earth observation. The Eradiate team acknowledges Mitsuba creators
and contributors for their work.

The development of Eradiate is funded by the
[Copernicus programme](https://www.copernicus.eu/) through a project managed by
the [European Space Agency](http://www.esa.int/) (contract no
40000127201/19/IBG).
The design phase was funded by the [MetEOC-3 project](http://www.meteoc.org/)
(EMPIR grant 16ENV03).

## Citing Eradiate

The most general citation is as follows:

```bibtex
@software{Eradiate,
    author = {Leroy, Vincent and Nollet, Yvan and Schunke, Sebastian and Misk, Nicolas and Marton, Nicolae and Govaerts, Yves},
    license = {LGPL-3.0},
    title = {Eradiate radiative transfer model},
    url = {https://github.com/eradiate/eradiate},
    doi = {10.5281/zenodo.7224314},
    year = {2024}
}
```

If you want to reference a specific version, you can update the previous
citation with `doi`, `year` and `version` fields populated with metadata
retrieved from our
[Zenodo records](https://zenodo.org/search?q=parent.id%3A7224314&f=allversions%3Atrue&l=list&p=1&s=10&sort=version).
Example:

```bibtex
@software{Eradiate,
    author = {Leroy, Vincent and Nollet, Yvan and Schunke, Sebastian and Misk, Nicolas and Marton, Nicolae and Govaerts, Yves},
    license = {LGPL-3.0},
    title = {Eradiate radiative transfer model},
    url = {https://github.com/eradiate/eradiate},
    doi = {10.5281/zenodo.13897261},
    year = {2024},
    version = {0.29.0},
}
```

## License

Eradiate is free software licensed under the
[GNU Lesser General Public License (v3)](./LICENSE).

## Project status

Eradiate is actively developed. It is beta software.

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