Seeking Functions for Phobos' Rotational Dynamics in Python

[luigigisolfi]

Question

User: Hi everyone 😃
I am trying to propagate the dynamics of Phobos and there are a couple of functions that I know exist but are either not exposed to Python or their documentation is missing.
One of them should be under the rotation_model module, and it creates a synchronous rotation model with a longitudinal libration. The other one provides the initial conditions for the integration of the rotational dynamics of Phobos that is compatible with the absence of free modes in Phobos' rotation. So it computes and returns the initial conditions that will not generate normal modes.
I was wondering if anyone knows the name/syntax of these functions and could give be a brief explanation on how to use them(?)
Thaaanks 😉

[luigigisolfi]

Answer

Tudat Team: The function for the damped rotational initial state is:
https://github.com/tudat-team/tudatpy/blob/master/tudatpy/kernel/expose_numerical_simulation/expose_propagation.cpp#L138
which exposes this function:
https://github.com/tudat-team/tudat/blob/master/include/tudat/astro/propagators/getZeroProperModeRotationalInitialState.h#L301-L328
which ultimately calls this function:
https://github.com/tudat-team/tudat/blob/master/include/tudat/astro/propagators/getZeroProperModeRotationalInitialState.h#L133-L299 (edited)
expose_propagation.cpp
https://github.com/[tudat-team/tudatpy](https://github.com/tudat-team/tudatpy)|tudat-team/tudatpytudat-team/tudatpy | Added by GitHub
getZeroProperModeRotationalInitialState.h
https://github.com/[tudat-team/tudat](https://github.com/tudat-team/tudat)|tudat-team/tudattudat-team/tudat | Added by GitHub
8:53
The synchronous rotation model is exposed to Python here:
https://github.com/tudat-team/tudatpy/blob/master/tudatpy/kernel/expose_numerical_simulation/expose_environment.cpp#L458-L464
Note that this is the rotation model (from the associated body), not the rotation model settings
You'll see that this rotation model has a libration_calculator property, and you can set an object of this class:
https://github.com/tudat-team/tudatpy/blob/master/tudatpy/kernel/expose_numerical_simulation/expose_environment.cpp#L450-L455
as libration_calculator . The associated C++ code can be found here:
https://github.com/tudat-team/tudat/blob/master/include/tudat/astro/ephemerides/synchronousRotationalEphemeris.h
and in the corresponding .cpp file

[luigigisolfi]

User: Thaanks 😉