Geopack-2008 C# .NET implementation

High-performance C# implementation of the Geopack-2008 geomagnetic field model with double-precision accuracy.

Validation • Benchmarks • Tech stack • Code Style • Licensing • How to cite • References

This library provides numerical accuracy matching the original Fortran code by N. A. Tsyganenko to within 12 decimal digits (8E-12D). For external magnetic field models, accuracy is raised to 13 digits (1E-13D).

Validation

The implementation is rigorously validated against the original Fortran code using our comprehensive testing framework with 100+ unit tests. See Unit Testing Framework for details on test data generation and verification procedures.

Benchmarks

Comprehensive performance benchmarks are available to measure the library's efficiency. For detailed benchmark results, methodology, and running instructions, see the benchmarks documentation.

Tech stack

• Supported .NET versions:
  • .NET 9
• Native AOT compilation
• Nullable reference types
• Central package management
• SLNX - simpler solution file format in the .NET CLI

Native AOT compilation

To build the project with native AOT compilation, execute the following command (depending on the target platform):

dotnet publish --framework net9.0 -c Release -r linux-x64

dotnet publish --framework net9.0 -c Release -r win-x64

dotnet publish --framework net9.0 -c Release -r osx-x64

Licensing

This C# implementation is a derivative work of the original FORTRAN code by Nikolai Tsyganenko, and is distributed under the same GNU GPL v3 license.

How to Cite

If you use this software in your research, please cite it using the following metadata:

APA Style: Nikolaev, A. V., Ermilov, A. O., & Tsyganenko, N. A. (2025). Geopack-2008 C# .NET implementation (Version v1.0.0) [Computer software]. Zenodo. https://doi.org/10.5281/zenodo.17437549

BibTeX:

@software{Geopack_2008_CSharp_2025,
  author = {Nikolaev, Alexander V. and Ermilov, Aleksei O. and Tsyganenko, Nikolai A.},
  doi = {10.5281/zenodo.17437549},
  license = {GPL-3.0-or-later},
  month = oct,
  title = {{Geopack-2008 C\# .NET implementation}},
  url = {https://github.com/Aurora-Science-Hub/Geopack},
  version = {v1.0.0},
  year = {2025}
}

References

The homepages of the original Geopack library and the associated scientific literature are available at the following links: old page and new page.

This implementation is based on and extends the following scientific works:

1. Tsyganenko, N. A. (2002). A model of the near magnetosphere with a dawn-dusk asymmetry 1. Mathematical structure. J. Geophys. Res., 107 (A8), https://doi.org/10.1029/2001JA000219

2. Tsyganenko, N. A., & Sitnov, M. I. (2005). Modeling the dynamics of the inner magnetosphere during strong geomagnetic storms. Journal of Geophysical Research: Space Physics, 110(A3), A03208. https://doi.org/10.1029/2004JA010798

3. Hapgood, M. A. (1992). Space physics coordinate transformations: A user guide. Planetary and Space Science, 40(5), 711–717. https://doi.org/10.1016/0032-0633(92)90012-D

4. Tsyganenko, N. A., Andreeva, V. A. (2016), An empirical RBF model of the magnetosphere parameterized by interplanetary and ground-based drivers, J. Geophys. Res. Space Physics, v.121(11), 10,786-10,802, https://doi.org/10.1002/2016JA023217