Licenses

cysgp4 itself is published under GPL v3, an open-source license. The package is a Cython-powered wrapper of the sgp4lib library (by Daniel Warner) to compute satellite positions from two-line elements (TLE). The sgp4lib source code is licensed under Apache-2.0 license

The package is partly based on the Astropy-affiliated package template, which is under BSD 3-clause license.