org.orekit.forces.gravity.potential

Interface SphericalHarmonicsProvider

All Superinterfaces:

TideSystemProvider

All Known Subinterfaces:

NormalizedSphericalHarmonicsProvider, RawSphericalHarmonicsProvider, UnnormalizedSphericalHarmonicsProvider

All Known Implementing Classes:

CachedNormalizedSphericalHarmonicsProvider

public interface SphericalHarmonicsProvider
extends TideSystemProvider

Interface used to provide spherical harmonics coefficients.

Two interfaces are provided to distinguish between normalized and un-normalized coefficients: NormalizedSphericalHarmonicsProvider and UnnormalizedSphericalHarmonicsProvider. To account for gravity pertubations all providers are capable of providing the coefficients on specific dates, using the onDate(AbsoluteDate) methods.

Typical usage when evaluating the geopotential:

     NormalizedSphericalHarmonicsProvider provider = ...;
     NormalizedShpericalHarmonics coeffs = provider.onDate(date);
     double c20 = coeffs.getNormalizedCnm(2, 0);
 

Since:

6.0

Author:

Luc Maisonobe

See Also:

GravityFields

Method Summary

Modifier and Type	Method and Description
double	getAe() Get the value of the central body reference radius.
int	getMaxDegree() Get the maximal supported degree.
int	getMaxOrder() Get the maximal supported order.
double	getMu() Get the central body attraction coefficient.
double	getOffset(AbsoluteDate date) Get the offset from reference date for the harmonics.
AbsoluteDate	getReferenceDate() Get the reference date for the harmonics.

Methods inherited from interface org.orekit.forces.gravity.potential.TideSystemProvider

getTideSystem

Method Detail

getMaxDegree

int getMaxDegree()

Get the maximal supported degree.

Returns:

maximal supported degree

getMaxOrder

int getMaxOrder()

Get the maximal supported order.

Returns:

maximal supported order

getMu

double getMu()

Get the central body attraction coefficient.

Returns:

mu (m³/s²)

getAe

double getAe()

Get the value of the central body reference radius.

Returns:

ae (m)

getReferenceDate

AbsoluteDate getReferenceDate()

Get the reference date for the harmonics.

Returns:

reference date for the harmonics

getOffset

double getOffset(AbsoluteDate date)

Get the offset from reference date for the harmonics.

Parameters:

date - current date

Returns:

offset between current date and reference date if there is a reference date, or 0.0 if there are no reference dates (i.e. if getReferenceDate() returns null)