[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
RE: [Orekit Users] multiple thrust calibration
Thank you for your clear answer.
I have opened the ticket (issue #338) on redmine today.
Sincerely,
Quentin
-----Original Message-----
From: orekit-users-request@orekit.org [mailto:orekit-users-request@orekit.org] On Behalf Of MAISONOBE Luc
Sent: Friday, May 05, 2017 3:50 PM
To: orekit-users@orekit.org
Subject: Re: [Orekit Users] multiple thrust calibration
"RHONE, Quentin" <quentin.rhone@airbus.com> a écrit :
> Hi all,
Hi Quentin,
>
> I need to perform a single orbit determination which covers several
> maneuvers. I want to calibrate the thrust of each maneuver
> separately but I cannot find the way to do it with the
> ConstantThrustManeuver class.
> The thrust parameterDriver name is declared "final static" so the
> estimator considers that all maneuvers have the same thrust. It
> eventually creates several rawDrivers that have the same value (even
> if the maneuvers initially have different thrust levels). Am I right
> or did I miss something ?
You are right ... and Orekit is wrong. Not being able to use different
maneuver configurations is indeed a really stupid error I can be blamed
for!
The fact the values are identical as soon as the same parameter name
appears in several differents model is however a feature and not a bug.
It was designed for example for central gravity coefficient, as this
coefficient should be the same despite it appears in different force
models (Newtonian attraction, spherical harmonics, relativity...). So
the bug is that we are not able to specify different names, not that
similar names are merged as one parameter only in the estimator.
Could you open a ticket on the forge so we do not forget to solve
the issue?
>
> I bypassed this problem by re-defining another maneuver class taking
> a ConstantThrustManeuver and a maneuver name as attributes and
> implementing AbstractForceModel but I don't find it satisfactory. Is
> there a better way to do it ?
No, I thing this is roughly the way to go. Perhaps we should use a
thruster name rather than a maneuver name, so if thruster "1A" is
used for maneuvers 1, 2 and 4 and thruster "2C" is used for maneuver 3,
then we could have 2 parameters to be estimated rather than 4.
I think we will add a new constructor with a thruster name parameter
in the existing class, the name being used as a prefix. So if users
use the existing constructor without thruster name the parameter
driver will be "thrust", but if they use the new constructor with
a name "1A" the parameter name will be "1A-thrust".
Thanks for the report.
Luc
>
> Thank you in advance for your answer,
>
> Quentin
>
>
> ***************************************************************
> 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