[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RE: [Orekit Developers] From osculating parameters to mean parameters for LEO orbits



Hi all,

The problem is solved with both the use of the DSST propagator and the trick.
Thank you for your help and for the note about what does the model include.

Best,

Lara

-----Original Message-----
From: orekit-developers-request@orekit.org [mailto:orekit-developers-request@orekit.org] On Behalf Of paulcefo
Sent: Monday, April 18, 2016 3:08 PM
To: orekit-developers@orekit.org
Cc: orekit-developers-request@orekit.org; HUE, Lara
Subject: Re: [Orekit Developers] From osculating parameters to mean parameters for LEO orbits

All,

I have started on a comment on the osculating to mean conversion. I will 
finish it later today but I wanted to send the current draft now.

regards,

Paul

-- 
Dr. Paul J. Cefola
Consultant in Aerospace Systems, Spaceflight Mechanics, & Astrodynamics
Adjunct Faculty, Dept. of Mechanical and Aerospace Engineering, 
University at Buffalo (SUNY)

4 Moonstone Way
Vineyard Haven, MA 02568
USA

508-696-1884 (phone on Martha's Vineyard)
978-201-1393 (cell)

paulcefo@buffalo.edu
paul.cefola@gmail.com

On 04/15/2016 7:52 am, HUE, Lara wrote:
> Hi to all,
> 
> Thanks for the use of the great Orekit tool !
> My question is about the computation of mean parameters from a LEO
> osculating orbit.
> In order to get some operational parameters, I need to compute the
> mean parameters at each steps of the global propagation.
> One way is to use the OsculatingToMeanElementsConverter with a
> specific propagator.
> I tried with a classical EcksteinHechlerPropagator, however the
> following exception has been raised :
> 
> Exception in thread "main" org.orekit.errors.PropagationException:
> impossible de calculer les paramètres moyens au sens de
> Eckstein-Hechler après 101 itérations
>  at
> org.orekit.propagation.analytical.EcksteinHechlerPropagator.<init>(EcksteinHechlerPropagator.java:318)
> 
>  at
> org.orekit.propagation.analytical.EcksteinHechlerPropagator.<init>(EcksteinHechlerPropagator.java:200)
> 
>  at main.Init.main(Init.java:91)
> Caused by: org.orekit.errors.PropagationException: impossible de
> calculer les paramètres moyens au sens de Eckstein-Hechler après 101
> itérations
>  at
> org.orekit.propagation.analytical.EcksteinHechlerPropagator.computeMeanParameters(EcksteinHechlerPropagator.java:394)
> 
>  at
> org.orekit.propagation.analytical.EcksteinHechlerPropagator.resetInitialState(EcksteinHechlerPropagator.java:327)
> 
>  at
> org.orekit.propagation.analytical.EcksteinHechlerPropagator.<init>(EcksteinHechlerPropagator.java:311)
> 
>  ... 2 more
> 
> Indeed, when calling the EcksteinHechlerPropagator constructor, it
> takes more than 100 iterations to compute mean parameters at the
> initial state, and therefore the exception is raised.
> Here is a specific orbit among others, retrieved from the simulation,
> for which the computation in mean elements is not possible :
> 
> AbsoluteDate t = NEW AbsoluteDate(2016, 07, 22, 9, 35, 42.562,
> TimeScalesFactory._getUTC_());
> Frame frame = FramesFactory._getEME2000_();
> Orbit orbit = NEW EquinoctialOrbit(7075842.806163763,
> 0.0012957331188810572, -4.760791390305797E-4, 0.14011350699555794,
> -1.1457596828634813, 79339.41232985309, PositionAngle._TRUE_, frame,
> t, Constants._WGS84_EARTH_MU_);
> Double mass = 436.5;
> DOUBLE c20 = Constants._EIGEN5C_EARTH_C20_;
> DOUBLE c30 = Constants._EIGEN5C_EARTH_C30_;
> DOUBLE c40 = Constants._EIGEN5C_EARTH_C40_;
> DOUBLE c50 = Constants._EIGEN5C_EARTH_C50_;
> DOUBLE c60 = Constants._EIGEN5C_EARTH_C60_;
> EcksteinHechlerPropagator analyticalPropagatorWrong = NEW
> EcksteinHechlerPropagator(orbit, mass,
> Constants._WGS84_EARTH_EQUATORIAL_RADIUS_, Constants._WGS84_EARTH_MU_,
> c20, c30, c40, c50, c60);
> 
> Is there a better way to convert osculating parameters to mean
> parameters?
> Best,
> 
> Lara Hué
> 
> ***************************************************************
> Ce courriel (incluant ses eventuelles pieces jointes) peut contenir
> des informations confidentielles et/ou protegees ou dont la diffusion
> est restreinte. Si vous avez recu ce courriel par erreur, vous ne
> devez ni le copier, ni l'utiliser, ni en divulguer le contenu a
> quiconque. Merci d'en avertir immediatement l'expediteur et d'effacer
> ce courriel de votre systeme. Airbus Defence and Space et les
> sociétés Airbus Group declinent toute responsabilite en cas de
> corruption par virus, d'alteration ou de falsification de ce courriel
> lors de sa transmission par voie electronique.
> This email (including any attachments) may contain confidential and/or
> privileged information or information otherwise protected from
> disclosure. If you are not the intended recipient, please notify the
> sender immediately, do not copy this message or any attachments and do
> not use it for any purpose or disclose its content to any person, but
> delete this message and any attachments from your system. Airbus
> Defence and Space and Airbus Group companies disclaim any and all
> liability if this email transmission was virus corrupted, altered or
> falsified.
> ---------------------------------------------------------------------
> Airbus Defence and Space SAS (393 341 516 RCS Versailles) - Capital:
> 16.587.728 EUR - Siege social: 51-61 Route de Verneuil, 78130 Les
> Mureaux, France
This mail has originated outside your organization, either from an external partner or the Global Internet.
Keep this in mind if you answer this message.



***************************************************************
Ce courriel (incluant ses eventuelles pieces jointes) peut contenir des informations confidentielles et/ou protegees ou dont la diffusion est restreinte. Si vous avez recu ce courriel par erreur, vous ne devez ni le copier, ni l'utiliser, ni en divulguer le contenu a quiconque. Merci d'en avertir immediatement l'expediteur et d'effacer ce courriel de votre systeme. Airbus Defence and Space et les sociétés Airbus Group declinent toute responsabilite en cas de corruption par virus, d'alteration ou de falsification de ce courriel lors de sa transmission par voie electronique.
This email (including any attachments) may contain confidential and/or privileged information or information otherwise protected from disclosure. If you are not the intended recipient, please notify the sender immediately, do not copy this message or any attachments and do not use it for any purpose or disclose its content to any person, but delete this message and any attachments from your system. Airbus Defence and Space and Airbus Group companies disclaim any and all liability if this email transmission was virus corrupted, altered or falsified. 
---------------------------------------------------------------------
Airbus Defence and Space SAS (393 341 516 RCS Versailles) - Capital: 16.587.728 EUR - Siege social: 51-61 Route de Verneuil, 78130 Les Mureaux, France