Re: [Orekit Users] Propagating with Threads (Error)

["Ward, Evan" <Evan.Ward@nrl.navy.mil>]

Hi Javier,

Don't share a Propagator between threads. I.e. make Satellite.propagator not static. Could you submit a bug to document that propagators are not thread-safe? It is currently documented for NumericalPropagator, but not TLEPropagator or Propagator. [1]

Altitude is in meters. Orekit uses m, s, rad, kg unless otherwise documented. Could you create a bug to document units there?

Patches are also welcome with the bugs if you would like to fix the issues.

Some other unsolicited advice. :) Use TLEPropagator.selectExtrapolator() instead of new SGP4(). [2] Use an ExecutorService [3] instead of Thread.

Best Regards,

Evan

[1] https://www.orekit.org/site-orekit-9.2/apidocs/org/orekit/propagation/numerical/NumericalPropagator.html

[2] https://www.orekit.org/site-orekit-9.2/apidocs/org/orekit/propagation/analytical/tle/TLEPropagator.html#selectExtrapolator-org.orekit.propagation.analytical.tle.TLE-org.orekit.attitudes.AttitudeProvider-double-

[3] https://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ExecutorService.html

On Fri, 2018-06-15 at 15:22 +0200, javier.montemayor.mancias@emi.fraunhofer.de wrote:

> Hi,
>
> I'm trying to run several propagations in parallel using threads. However, I
> get either a NullPointerException or an Orekit Exception "interval does not
> bracket a root: f(0) = 0,01, f(60) = 0,042". I am using elevation detectors,
> when I do not use them, the error does not happen.
>
> Any ideas on how to make this right?
> Here's the GitHub for the project:
> https://github.com/jmontemayorm/Satellite_Orbit_Analyzer
>
> Best regards,
> Javier
>
> P.S.: Does anybody know if the altitude argument for GeodeticPoint is in
> meters or km?