SphericalHarmonicsProvider (ORbit Extrapolation KIT 9.3 API)

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:

GravityFieldFactory

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	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)