Ephemeris* PlatformPosition::Interpolate(JSDDateTime date)
{
const double JOURCIVIL_LENGTH = 86400.0 ;
Ephemeris* ephem = NULL;
if (_nbrData<=1)
{
std::cout << "a..." << std::endl;
ephem = NULL;
}
else
{
/*
* The first element of the list is cloned to ensure that the output ephemeris is expressed in the same coordinate system as input ones
*/
ephem = _data[0]->Clone();
/* NORMAL CASE */
/*------------*/
double * x = new double[_nbrData];
double * y = new double[_nbrData];
double * yd = new double[_nbrData];
double dt = 0.0;
//double d;
x[0] = 0.0 ;
for (int i = 1 ; i < _nbrData ; i++)
{
x[i] = (_data[i]->get_date().get_day0hTU().get_julianDate() - _data[0]->get_date().get_day0hTU().get_julianDate())
* JOURCIVIL_LENGTH
+ _data[i]->get_date().get_second() - _data[0]->get_date().get_second()
+ _data[i]->get_date().get_decimal() - _data[0]->get_date().get_decimal();
}
if (ephem != NULL)
{
ephem->set_date(date);
dt = (date.get_day0hTU().get_julianDate() - _data[0]->get_date().get_day0hTU().get_julianDate()) * JOURCIVIL_LENGTH
+ date.get_second() - _data[0]->get_date().get_second()
+ date.get_decimal() - _data[0]->get_date().get_decimal();
/* Computation by Everett */
/*---------------------*/
double pos[3];
double vit[3];
for (int j = 0 ; j < 3 ; j++)
{
for (int i = 0 ; i < _nbrData ; i++)
{
y[i] = _data[i]->get_position()[j] ;
yd[i] = _data[i]->get_vitesse()[j] ;
}
HermiteInterpolator interpolator(_nbrData,x,y,yd);
interpolator.Interpolate(dt, pos[j], vit[j]);
}
ephem->set_position(pos);
ephem->set_vitesse(vit);
}
delete[] x;
delete[] y;
delete[] yd;
}
return ephem;
}
