Re: [Orekit Users] DSSTPropagator isOsculating

[paulcefo <paulcefo@buffalo.edu>]

I want to point out that the thread that was generated by Elisabet on 22 
March is useful in understanding the java code for the DSST tesseral 
linear combination short-periodic terms.

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 03/24/2016 5:01 am, MAISONOBE Luc wrote:
> Elisabet <elisabet.cid-borobia@thalesaleniaspace.com> a écrit :
>
> > Hello,
> >
> > Luc, your code also works for me. The error occurs when the earthOrder 
> > is
> > different from 0 in the UnnormalizedSphericalHarmonicsProvider. There 
> > is not
> > any problem if : 
> > GravityFieldFactory.getUnnormalizedProvider(earthDegree,0);
> > However, it throws an arithmetic error when:
> > GravityFieldFactory.getUnnormalizedProvider(earthDegree,EarthOrder);
> >
> > Could you verify this?
>
> Still no problems.
>
> When I call GravityFieldFactory.getUnnormalizedProvider(earthDegree,
> earthOrder) with
> earthOrder set to 4 (instead of forced to 0 as in my previous mail), I
>  get this:
>
> mean:       equinoctial parameters: {a: 7120000.0; ex:
> -9.743700647852352E-4; ey: 2.2495105434386478E-4; hx:
> 0.39375193676896686; hy: 0.4222472565026574; lv: 179.0;}
> osculating: equinoctial parameters: {a: 7119197.746018779; ex:
> -7.268671251360758E-4; ey: 5.352135157065923E-4; hx:
> 0.3938711876441645; hy: 0.4221175844115694; lv: 178.98823442719726;}
>
> So the osculating parameters are different from the previous ones,
> which is expected.
>
> I don't get any exceptions.
>
> Could you send the full stack trace of the exception you get? What are
>  the non-zero degree order you use?
>
> With the current development code, I do get an exception when degree
> and order are set to 2,
> but it is an ArrayIndexOutOfBoundException, not an
> ArithmeticException. I'll investigate
> that one.
>
> best regards,
> Luc
>
> > Best regards,
> >
> > Elisabet