keplertools

keplertools provides a variety of methods for the propagation of two-body orbits.

Installation

To install from PyPI:

pip install keplertools

To install from source, clone or download the code repository, and, in the top level directory run:

pip install .

Installing from source requires a C compiler. See here for details: https://cython.readthedocs.io/en/latest/src/quickstart/install.html

Closed-Orbit Methods

The following methods are for use with closed orbits:

• eccanom() - Finds eccentric anomaly from mean anomaly and eccentricity. Can handle multiple different eccentricity values for different mean anomalies.

• eccanom_orvara() - Finds eccentric anomaly E, sinE, cosE from mean anomaly and eccentricity using methodologies from the orvara code. Can only handle one eccentricity value for all mean anomalies.

• trueanom() - Finds true anomaly from eccentric anomaly and eccentricity.

• vec2orbElem() - Convert position and velocity vectors to Keplerian orbital elements using (corrected) algorithm from [Vinti1998].

• vec2orbElem2() - Convert position and velocity vectors to Keplerian orbital elements using algorithm from [Vallado2013].

• orbElem2vec() - Convert Keplerian orbital elements to position and velocity vectors.

All-Orbit Methods

The following methods support all orbits (open and closed):

• invKepler() - Finds eccentric/hyperbolic/parabolic anomaly from mean anomaly and eccentricity. Can also return true anomaly. Works for single or multiple eccentricity values.

• kepler2orbstate() - Calculate orbital state vectors from Keplerian elements.

• orbstate2kepler()- Calculate Keplerian elements given orbital state vectors.

• universalfg() - Propagate orbital state vectors by delta t via universal variable-based f and g.

• planSys - Propagate orbital state vectors using (exact) Kepler state transition matrix. Implements algorithms from [Shepperd1985] and [Vallado2013].

Radial Velocity Methods

• calc_RV_from_M() - Calculate the combined radial velocity of a system of n objects at m epochs given mean anomalies.

• calc_RV_from_time() - Calculate the combined radial velocity of a system of n objects at m epochs given times.

Contents:

• keplertools
  • keplertools package
    • Submodules
    • keplertools.CyKeplerSTM module
      • CyKeplerSTM()
    • keplertools.CyRV module
      • CyRV_from_E()
      • CyRV_from_time()
    • keplertools.Cyeccanom module
      • Cyeccanom()
      • Cyeccanom_orvara()
    • keplertools.angutils module
    • keplertools.fun module
      • RV_from_time_py()
      • c2c3()
      • calcAB()
      • calc_RV_from_M()
      • calc_RV_from_time()
      • eccanom()
      • eccanom_orvara()
      • forcendarray()
      • invKepler()
      • kepler2orbstate()
      • orbElem2vec()
      • orbstate2kepler()
      • orvara_vector_helper()
      • true2eccanom()
      • trueanom()
      • unitvector()
      • universalfg()
      • validateOrbitalStateInputs()
      • vec2orbElem()
      • vec2orbElem2()
    • keplertools.keplerSTM module
      • planSys
    • Module contents
• References

Indices and tables

• Index

• Module Index

• Search Page