search

tudat-team / tudat

A C++ platform to perform astrodynamics and space research.
BSD 3-Clause "New" or "Revised" License
17 stars 28 forks source link

Solar activity not found when starting in monthly predictions #38

Closed gaffarelj closed 2 years ago

gaffarelj commented 2 years ago

It appears that no solar activity can be found when a simulation starts more than 7257.5 JD after J2000 (the 14th of November 2019). This was discovered using the nrlmsise00 atmosphere model that uses solar activity as an input.

However, starting before 7257.5 JD and propagating for years works.

Coincidentally, the space weather resource file switches from daily predictions to monthly predictions the14th of November 2019.

Coincidence? No, manually updating the data to a more recent space weather, the switch from daily predictions to monthly predictions is on the 20th of February 2022. Sure enough, the same error as before still happens, but now for this new date.

In short: starting a simulation at a time where the space weather is in monthly predictions causes the solar activity data to be inaccessible while starting in observations or daily predictions and then later switching to monthly predictions seems to work fine.

DominicDirkx commented 2 years ago

Good point, I think we should update this on two fronts:

DominicDirkx commented 2 years ago

I've made a few modifications to the NRLMSISE functions:

https://github.com/tudat-team/tudat/tree/feature/nrlmsise_update https://github.com/tudat-team/tudatpy/tree/feature/nrlmsise_update

It's now possible to use the predictions from the space weather file. As it turns out, this was quite straightforward, as these data were already loaded.

I have extended the unit tests to check if it's possible to use the monthly predictions (it is), but I don't have any reference data directly handy. Doing this would require a separate manual run of the NRLMSISE00 code.

DominicDirkx commented 2 years ago

Closing issues; remaining issue(s) being tracked through https://github.com/tudat-team/tudat/issues/40