//---------------------------------------------------------------------------
float Ionosphere::ElectronDensity(Rvector3 pos2, Rvector3 pos1)
{
// the fisrt position's latitude and longitude (unit: degree):
//real latitude = (real)(GmatMathConstants::PI_OVER_TWO_DEG - acos(pos1.Get(2)/pos1.GetMagnitude())*GmatMathConstants::DEG_PER_RAD); // unit: degree
real latitude = (real)(asin(pos1.Get(2)/pos1.GetMagnitude())*GmatMathConstants::DEG_PER_RAD); // unit: degree
real longitude = (real)(atan2(pos1.Get(1),pos1.Get(0))*GmatMathConstants::DEG_PER_RAD); // unit: degree
// mmag = 0 geographic =1 geomagnetic coordinates
integer jmag = 0; // 1;
// jf(1:30) =.true./.false. flags; explained in IRISUB.FOR
logical jf[31];
for (int i=1; i <= 30; ++i)
jf[i] = TRUE_;
jf[5] = FALSE_;
jf[6] = FALSE_;
jf[23] = FALSE_;
jf[29] = FALSE_;
jf[30] = FALSE_;
// jf[21] = FALSE_;
// jf[28] = FALSE_;
// iy,md date as yyyy and mmdd (or -ddd)
// hour decimal hours LT (or UT+25)
integer iy = (integer)yyyy;
integer md = (integer)mmdd;
real hour = (real)hours;
// Upper and lower integration limits
real hbeg = (real)(pos1.GetMagnitude() - earthRadius); // 0
real hend = hbeg;
real hstp = 1.0;
integer error = 0;
real outf[20*501+1];
real oarr[51];
// iri_sub(&jf[1], &jmag, &latitude, &longitude, &iy, &md, &hour,
// &hbeg, &hend, &hstp, &outf[21], &oarr[1], &error);
integer ivar = 1; // get attitude result
integer iut = 1; // 1 for universal time; 0 for local time
# ifdef DEBUG_IONOSPHERE_ELECT_DENSITY
MessageInterface::ShowMessage(" .At time = %lf A1Mjd:",epoch);
MessageInterface::ShowMessage(" year = %d md = %d hour = %lf h, time type = %s,\n", iy, md, hour, (iut?"Universal":"Local"));
MessageInterface::ShowMessage(" At position (x,y,z) = (%lf, %lf, %lf)km in Earth fixed coordinate system: ", pos1[0], pos1[1], pos1[2]);
MessageInterface::ShowMessage("(latitude = %lf degree, longitude = %lf degree, attitude = %lf km, ", latitude, longitude, hbeg);
MessageInterface::ShowMessage("coordinate system type = %s)\n",(jmag?"Geomagetic":"Geographic"));
#endif
iri_web(&jmag, &jf[1], &latitude, &longitude, &iy, &md, &iut, &hour, &hbeg, &hbeg,
&ivar, &hbeg, &hend, &hstp, &outf[21], &oarr[1], &error);
if (error != 0)
{
MessageInterface::ShowMessage("Ionosphere data files not found\n");
throw new MeasurementException("Ionosphere data files not found\n");
}
real density = outf[20+1];
if (density < 0)
density = 0;
#ifdef DEBUG_IONOSPHERE_ELECT_DENSITY
MessageInterface::ShowMessage(" Electron density at that time and location = %le electrons per m3.\n", density);
#endif
return density; //*(pos2-pos1).GetMagnitude();
}
//------------------------------------------------------------------------------
Integer CoordUtil::ComputeCartToKepl(Real grav, Real r[3], Real v[3], Real *tfp,
Real elem[6], Real *ma)
{
#ifdef DEBUG_CART_TO_KEPL
MessageInterface::ShowMessage(wxT("CoordUtil::ComputeCartToKepl called ... \n"));
MessageInterface::ShowMessage(wxT(" grav = %12.10f\n"), grav);
MessageInterface::ShowMessage(wxT(" KEP_ECC_TOL = %12.10f\n"), GmatOrbitConstants::KEP_ECC_TOL);
#endif
if (Abs(grav) < 1E-30)
return(2);
Rvector3 pos(r[0], r[1], r[2]);
Rvector3 vel(v[0], v[1], v[2]);
// eqn 4.1
Rvector3 angMomentum = Cross(pos, vel);
// eqn 4.2
Real h = angMomentum.GetMagnitude();
#ifdef DEBUG_CART_TO_KEPL
MessageInterface::ShowMessage(
wxT(" in ComputeCartToKepl, pos = %12.10f %12.10f %12.10f \n"), pos[0], pos[1], pos[2]);
MessageInterface::ShowMessage(
wxT(" in ComputeCartToKepl, vel = %12.10f %12.10f %12.10f \n"), vel[0], vel[1], vel[2]);
MessageInterface::ShowMessage(
wxT(" in ComputeCartToKepl, angMomentum = %12.10f %12.10f %12.10f\n"),
angMomentum[0], angMomentum[1], angMomentum[2]);
MessageInterface::ShowMessage(
wxT(" in ComputeCartToKepl, h = %12.10f\n"), h);
#endif
// if (h < 1E-30)
// {
// return 1;
// }
// eqn 4.3
Rvector3 nodeVec = Cross(Rvector3(0,0,1), angMomentum);
// eqn 4.4
Real n = nodeVec.GetMagnitude();
// eqn 4.5 - 4.6
Real posMag = pos.GetMagnitude();
Real velMag = vel.GetMagnitude();
// eqn 4.7 - 4.8
Rvector3 eccVec = (1/grav)*((velMag*velMag - grav/posMag)*pos - (pos * vel) * vel);
Real e = eccVec.GetMagnitude();
// eqn 4.9
Real zeta = 0.5*velMag*velMag - grav/posMag;
#ifdef DEBUG_CART_TO_KEPL
MessageInterface::ShowMessage(
wxT(" in ComputeCartToKepl, nodeVec = %12.10f %12.10f %12.10f \n"),
nodeVec[0], nodeVec[1], nodeVec[2]);
MessageInterface::ShowMessage(
wxT(" in ComputeCartToKepl, n = %12.10f\n"), n);
MessageInterface::ShowMessage(
wxT(" in ComputeCartToKepl, posMag = %12.10f\n"), posMag);
MessageInterface::ShowMessage(
wxT(" in ComputeCartToKepl, velMag = %12.10f\n"), velMag);
MessageInterface::ShowMessage(
wxT(" in ComputeCartToKepl, eccVec = %12.10f %12.10f %12.10f \n"), eccVec[0], eccVec[1], eccVec[2]);
MessageInterface::ShowMessage(
wxT(" in ComputeCartToKepl, e = %12.10f\n"), e);
MessageInterface::ShowMessage(
wxT(" in ComputeCartToKepl, zeta = %12.10f\n"), zeta);
MessageInterface::ShowMessage(
wxT(" in ComputeCartToKepl, Abs(1.0 - e) = %12.10f\n"), Abs(1.0 - e));
#endif
if ((Abs(1.0 - e)) <= GmatOrbitConstants::KEP_ECC_TOL)
{
wxString errmsg = wxT("Error in conversion to Keplerian state: ");
errmsg += wxT("The state results in an orbit that is nearly parabolic.\n");
throw UtilityException(errmsg);
}
// eqn 4.10
Real sma = -grav/(2*zeta);
#ifdef DEBUG_CART_TO_KEPL
MessageInterface::ShowMessage(
wxT(" in ComputeCartToKepl, sma = %12.10f\n"), sma);
#endif
if (Abs(sma*(1 - e)) < .001)
{
throw UtilityException
(wxT("Error in conversion from Cartesian to Keplerian state: ")
wxT("The state results in a singular conic section with radius of periapsis less than 1 m.\n"));
// (wxT("CoordUtil::CartesianToKeplerian() ")
// wxT("Warning: A nearly singular conic section was encountered while ")
// wxT("converting from the Cartesian state to the Keplerian elements. The radius of ")
// wxT("periapsis must be greater than 1 meter.\n"));
}
// eqn 4.11
Real i = ACos( angMomentum.Get(2)/h );
if (i >= PI - GmatOrbitConstants::KEP_TOL)
{
throw UtilityException
(wxT("Error in conversion to Keplerian state: ")
wxT("GMAT does not currently support orbits with inclination of 180 degrees.\n"));
}
Real raan, argPeriapsis, trueAnom;
raan=argPeriapsis=trueAnom=0;
if ( e >= 1E-11 && i >= 1E-11 ) // CASE 1: Non-circular, Inclined Orbit
{
raan = ACos( nodeVec.Get(0)/n );
if (nodeVec.Get(1) < 0)
raan = TWO_PI - raan;
argPeriapsis = ACos( (nodeVec*eccVec)/(n*e) );
if (eccVec.Get(2) < 0)
argPeriapsis = TWO_PI - argPeriapsis;
trueAnom = ACos( (eccVec*pos)/(e*posMag) );
if (pos*vel < 0)
trueAnom = TWO_PI - trueAnom;
}
if ( e >= 1E-11 && i < 1E-11 ) // CASE 2: Non-circular, Equatorial Orbit
{
raan = 0;
argPeriapsis = ACos(eccVec.Get(0)/e);
if (eccVec.Get(1) < 0)
argPeriapsis = TWO_PI - argPeriapsis;
trueAnom = ACos( (eccVec*pos)/(e*posMag) );
if (pos*vel < 0)
trueAnom = TWO_PI - trueAnom;
}
if ( e < 1E-11 && i >= 1E-11 ) // CASE 3: Circular, Inclined Orbit
{
raan = ACos( nodeVec.Get(0)/n );
if (nodeVec.Get(1) < 0)
raan = TWO_PI - raan;
argPeriapsis = 0;
trueAnom = ACos( (nodeVec*pos)/(n*posMag) );
if (pos.Get(2) < 0)
trueAnom = TWO_PI - trueAnom;
}
if ( e < 1E-11 && i < 1E-11 ) // CASE 4: Circular, Equatorial Orbit
{
raan = 0;
argPeriapsis = 0;
trueAnom = ACos(pos.Get(0)/posMag);
if (pos.Get(1) < 0)
trueAnom = TWO_PI - trueAnom;
}
elem[0] = sma;
elem[1] = e;
elem[2] = i*DEG_PER_RAD;
elem[3] = raan*DEG_PER_RAD;
elem[4] = argPeriapsis*DEG_PER_RAD;
elem[5] = trueAnom*DEG_PER_RAD;
return 0;
}