Interpolation methods.
| Member | Value | Description | 
|---|---|---|
| eInterpolationMethodUnknown | -1 | Unknown or unsupported interpolation method. | 
| eHermitian | 0 | Hermitian: uses the position and velocity ephemeris to interpolate position and velocity together. | 
| eLagrange | 1 | Lagrange: interpolates position and velocity separately. | 
| eVOP | 2 | VOP: a special interpolator that deals well with ephemeris produced at a large step size. | 





