39 lines
1.3 KiB
C++
39 lines
1.3 KiB
C++
#include "Eci.h"
|
|
|
|
Eci::Eci(const Julian &date, const CoordGeodetic &geo)
|
|
: date_(date) {
|
|
|
|
static const double mfactor = Globals::TWOPI() * (Globals::OMEGA_E() / Globals::SEC_PER_DAY());
|
|
const double latitude = geo.GetLatitude();
|
|
const double longitude = geo.GetLongitude();
|
|
const double altitude = geo.GetAltitude();
|
|
|
|
/*
|
|
* Calculate Local Mean Sidereal Time for observers longitude
|
|
*/
|
|
const double theta = date_.ToLMST(longitude);
|
|
|
|
const double c = 1.0 / sqrt(1.0 + Globals::F() * (Globals::F() - 2.0) * pow(sin(latitude), 2.0));
|
|
const double s = pow(1.0 - Globals::F(), 2.0) * c;
|
|
const double achcp = (Globals::XKMPER() * c + altitude) * cos(latitude);
|
|
|
|
position_.SetX(achcp * cos(theta));
|
|
position_.SetY(achcp * sin(theta));
|
|
|
|
position_.SetZ((Globals::XKMPER() * s + altitude) * sin(latitude));
|
|
position_.SetW(sqrt(pow(position_.GetX(), 2.0) + pow(position_.GetY(), 2.0) + pow(position_.GetZ(), 2.0)));
|
|
|
|
velocity_.SetX(-mfactor * position_.GetY());
|
|
velocity_.SetY(mfactor * position_.GetX());
|
|
velocity_.SetZ(0.0);
|
|
velocity_.SetW(sqrt(pow(velocity_.GetX(), 2.0) + pow(velocity_.GetY(), 2.0)));
|
|
}
|
|
|
|
Eci::Eci(const Julian &date, const Vector &position, const Vector &velocity)
|
|
: date_(date), position_(position), velocity_(velocity) {
|
|
|
|
}
|
|
|
|
Eci::~Eci(void) {
|
|
}
|