// $Header: /cvs/gled-1.2/Numerica/Glasses/Moonraker.cxx,v 1.5 2005/06/06 15:41:17 matevz Exp $
// Copyright (C) 1999-2005, Matevz Tadel. All rights reserved.
// This file is part of GLED, released under GNU General Public License version 2.
// For the licensing terms see $GLEDSYS/LICENSE or http://www.gnu.org/.
//________________________________________________________________________
// Moonraker
//
// An example for ODECrawler.
// Integrates movement of a shell fired from Earth in Earth-Moon system.
// Units: distance ~ earth radius; time ~ day
// mass ~ earth mass
// V0 = 1 means escape velocity from earth
//________________________________________________________________________
#include "Moonraker.h"
ClassImp(Moonraker)
void Moonraker::_init()
{
mODECrawler = 0;
Double_t earth_mass=5.9736e24, em_dist=383200e3, month=656*3600, kappa=6.673e-11;
Double_t earth_r=6378e3, day=24*3600;
hKappa = kappa*earth_mass*day*day/earth_r/earth_r/earth_r;
hEscapeVelocity = TMath::Sqrt(2*hKappa);
mT0Moon = 27.3333; mRMoon = 0.2725; mMMoon = 0.0123; mDMoon = 60.0815;
mV0 = 1;
// cout <<"Kappa="<< hKappa <<"tEscVel="<< hEscapeVelocity <<endl;
mT = 0; mT0 = 0; mT1 = 2;
mScale = 1; mLOD = 20;
mEColor.rgba(0.2, 0.6, 0.8);
mMColor.rgba(0.2, 1, 0.2);
mSColor.rgba(1,0.5,0.5); mRShell = 0.1;
mTColor.rgba(1,1,1); mTWidth = 1;
}
void Moonraker::MoonPos(Double_t* r, Double_t t) const
{
r[0] = mDMoon*TMath::Cos(2*TMath::Pi()/mT0Moon*t);
r[1] = mDMoon*TMath::Sin(2*TMath::Pi()/mT0Moon*t);
r[2] = 0;
}
void Moonraker::MoonPos(TVector3& r, Double_t t) const
{
r.SetXYZ(mDMoon*TMath::Cos(2*TMath::Pi()/mT0Moon*t),
mDMoon*TMath::Sin(2*TMath::Pi()/mT0Moon*t),
0);
}
/**************************************************************************/
namespace {
inline Double_t p223(Double_t x) { return x*TMath::Sqrt(x); }
}
void
Moonraker::ODEDerivatives(const Double_t x, const TVectorD& y, TVectorD& d)
{
TVector3 pos(y(0), y(1), y(2));
TVector3 moon; MoonPos(moon, x);
TVector3 md(pos);
md -= moon;
Double_t r0 = p223(pos.Mag2());
Double_t r1 = p223(md.Mag2());
for(UInt_t i=0; i<3; i++) {
d(i) = y(i+3u);
d(i+3u) = -hKappa*(pos(i)/r0 + md(i)/r1*mMMoon);
}
}
void
Moonraker::ODEStart(TVectorD& v, Double_t& x1, Double_t& x2)
{
Double_t phi = 2*TMath::Pi()*mT0 + mLon*TMath::DegToRad(),
theta = mLat*TMath::DegToRad();
v(0) = TMath::Cos(phi)*TMath::Cos(theta);
v(1) = TMath::Sin(phi)*TMath::Cos(theta);
v(2) = TMath::Sin(theta);
TVectorF z(3);
for(Int_t i=0; i<3; i++) z(i) = mV0*hEscapeVelocity*v(i);
ZTrans t; t.SetRotByAngles(mPhi*TMath::Pi()/180, mTheta*TMath::Pi()/180, 0);
t.Rot3Vec(z);
for(Int_t i=0; i<3; i++) v(i + 3) = z(i);
x1 = mT0; x2 = mT1;
}
/**************************************************************************/
#include "Moonraker.c7"
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