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Re: [Orekit Users] DSSTPropagator isOsculating

May I ask a question about the purpose of 36 x 4?
For a LEO orbit, going from 36x0 to 36x4 will just be adding some periodic content. 

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 03/24/2016 8:25 am, MAISONOBE Luc wrote:

Elisabet <elisabet.cid-borobia@thalesaleniaspace.com> a écrit :


Hello Luc,
In my case the earthDegree=36 and the earthOrder=4. It seems it throws the exception each time the earthDegree is different from the earthOrder. The DSSTPropagator, using mean parameters, can be used with these Earth’s degree and order. However, it throws the thread when using osculating parameters. 

I finally managed to reproduce the error!
I first tried simply having different values for degree and order, but
still got a result.

Using (36, 4), I finally got the same exception as you!

I will look at this issue, stay tuned.

best regards,
Luc



The thread:
Exception in thread "main"
org.apache.commons.math3.exception.MathArithmeticException: erreur
arithmétique
	at
org.apache.commons.math3.util.ArithmeticUtils.mulAndCheck(ArithmeticUtils.java:582)
	at
org.apache.commons.math3.util.ArithmeticUtils.mulAndCheck(ArithmeticUtils.java:552)
	at
org.apache.commons.math3.util.CombinatoricsUtils.binomialCoefficient(CombinatoricsUtils.java:126)
	at
org.apache.commons.math3.analysis.polynomials.PolynomialsUtils.shift(PolynomialsUtils.java:329)
	at
org.orekit.propagation.semianalytical.dsst.utilities.NewcombOperators
$PolynomialsGenerator.shiftList(NewcombOperators.java:326)
	at
org.orekit.propagation.semianalytical.dsst.utilities.NewcombOperators
$PolynomialsGenerator.computeFor(NewcombOperators.java:216)
	at
org.orekit.propagation.semianalytical.dsst.utilities.NewcombOperators
$PolynomialsGenerator.getPolynomials(NewcombOperators.java:175)
	at
org.orekit.propagation.semianalytical.dsst.utilities.NewcombOperators
$PolynomialsGenerator.access$000(NewcombOperators.java:104)
	at
org.orekit.propagation.semianalytical.dsst.utilities.NewcombOperators.getValue(NewcombOperators.java:86)
	at
org.orekit.propagation.semianalytical.dsst.utilities.hansen.HansenTesseralLinear
$HansenCoefficientsBySeries.generatePolynomial(HansenTesseralLinear.java:516)
	at
org.orekit.propagation.semianalytical.dsst.utilities.hansen.HansenTesseralLinear
$HansenCoefficientsBySeries.<init>(HansenTesseralLinear.java:472)
	at
org.orekit.propagation.semianalytical.dsst.utilities.hansen.HansenTesseralLinear.<init>(HansenTesseralLinear.java:100)
	at
org.orekit.propagation.semianalytical.dsst.forces.TesseralContribution.createHansenObjects(TesseralContribution.java:398)
	at
org.orekit.propagation.semianalytical.dsst.forces.TesseralContribution.initialize(TesseralContribution.java:334)
	at
org.orekit.propagation.semianalytical.dsst.forces.DSSTCentralBody.initialize(DSSTCentralBody.java:134)
	at
org.orekit.propagation.semianalytical.dsst.DSSTPropagator.computeOsculatingState(DSSTPropagator.java:338)

Best regards,

Elisabet