org.orekit.propagation.semianalytical.dsst.forces

Class AbstractGaussianContribution.GaussianShortPeriodicCoefficients

java.lang.Object

org.orekit.propagation.semianalytical.dsst.forces.AbstractGaussianContribution.GaussianShortPeriodicCoefficients

All Implemented Interfaces:

ShortPeriodTerms

Enclosing class:

AbstractGaussianContribution

protected static class AbstractGaussianContribution.GaussianShortPeriodicCoefficients
extends Object
implements ShortPeriodTerms

This class handles the short periodic coefficients described in Danielson 2.5.3-26.

The value of M is 0. Also, since the values of the Fourier coefficient D_i^m is 0 then the values of the coefficients D_i^m for m > 2 are also 0.

Author:

Petre Bazavan, Lucian Barbulescu

Method Summary

Modifier and Type	Method and Description
AbstractGaussianContribution.Slot	createSlot(SpacecraftState... meanStates) Get the slot valid for some date.
Map<String,double[]>	getCoefficients(AbsoluteDate date, Set<String> selected) Computes the coefficients involved in the contributions.
String	getCoefficientsKeyPrefix() Get the prefix for short period coefficients keys.
double[]	value(Orbit meanOrbit) Evaluate the contributions of the short period terms.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

createSlot

public AbstractGaussianContribution.Slot createSlot(SpacecraftState... meanStates)

Get the slot valid for some date.

Parameters:

meanStates - mean states defining the slot

Returns:

slot valid at the specified date

value

public double[] value(Orbit meanOrbit)

Evaluate the contributions of the short period terms.

Specified by:

value in interface ShortPeriodTerms

Parameters:

meanOrbit - mean orbit to which the short period contribution applies

Returns:

short period terms contributions

getCoefficientsKeyPrefix

public String getCoefficientsKeyPrefix()

Get the prefix for short period coefficients keys.

This prefix is used to identify the coefficients of the current force model from the coefficients pertaining to other force models. All the keys in the map returned by ShortPeriodTerms.getCoefficients(AbsoluteDate, Set) start with this prefix, which must be unique among all providers.

Specified by:

getCoefficientsKeyPrefix in interface ShortPeriodTerms

Returns:

the prefix for short periodic coefficients keys

See Also:

ShortPeriodTerms.getCoefficients(AbsoluteDate, Set)

getCoefficients

public Map<String,double[]> getCoefficients(AbsoluteDate date,
                                            Set<String> selected)

Computes the coefficients involved in the contributions.

This method is intended mainly for validation purposes. Its output is highly dependent on the implementation details in each force model and may change from version to version. It is not recommended to use it for any operational purposes.

For Gaussian forces, there are JMAX cj coefficients, JMAX sj coefficients and 3 dj coefficients. As JMAX = 12, this sums up to 27 coefficients. The j index is the integer multiplier for the true longitude argument in the cj and sj coefficients and to the degree in the polynomial dj coefficients.

Specified by:

getCoefficients in interface ShortPeriodTerms

Parameters:

date - current date

selected - set of coefficients that should be put in the map (empty set means all coefficients are selected)

Returns:

the selected coefficients of the short periodic variations, in a map where all keys start with ShortPeriodTerms.getCoefficientsKeyPrefix()