Orbit Determination Code

[DominicDirkx]

Based on the extensive development in my own personal Tudat branch (not all on Github), the Tudat code base will be expanded with orbit determination functionality, including the associated propagation of variational equations, observation models, least squares adjustment, observation corrections, observation partials, etc. This represents a significant extension of Tudat and will be handled in stages. Current progress can be seen in the OrbitDetermination branch of my personal Tudat fork

[DominicDirkx]

A quick update on this extensive feature:

The propagation of the variational equations has now been implemented, with analytical partial derivatives for most types of accelerations implemented.

Progress is currently ongoing on extending the suite of observation models and associated partials. The code is mostly ready (including unit tests), but is missing comments in many places (https://github.com/DominicDirkx/tudat/tree/ObservationPartials)

A pull request has been opened for new code that can be used to define ground stations.

The next step is to include an automatic routine to perform least-squares estimation, after which we will have a first iteration of functional orbit determination in Tudat!

[DominicDirkx]

The first iteration of the full orbit determination code (with simulated data) is now on my github account:

https://github.com/DominicDirkx/tudat/tree/OrbitDetermination

Unit tests are including, convergence of initial position estimation at the sub-micron level is demonstrated with long double dynamics/observations, ideal three-dimensional observations and no differences between truth and estimation models.

Some slight extensions of unit tests and significant addition of comments are required before this can be made into a pull request.

[DominicDirkx]

This functionality is now in pull request #153, #157, #158, #167 and #168. I'm closing this issue, as future information will be communicated through these pull requests.