SpiceyPy implementation of Vallado and Alfano, 2014, Curvilinear coordinate transformations for relative motion
cf. Celest Mech Dyn Astr (2014) 118:253–271, DOI 10.1007/s10569-014-9531-1
SpiceyPy: [https://github.com/AndrewAnnex/SpiceyPy]
SciPy
integral(sqrt(1 - k**2 sin(t)**2)
Used to calculate arc lengths along an ellipse
implements IEISK
testelit.f is command-line manual interface to elit.f