FTimeFitModel.cc

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#include <utl/PhysicalConstants.h>
#include <utl/ErrorLogger.h>
#include <utl/UTMPoint.h>
#include <det/Detector.h>
#include <fdet/FDetector.h>
#include <fdet/Eye.h>
#include <fdet/Telescope.h>
#include <utl/Point.h>
#include <fdet/FTimeFitModel.h>
#include <atm/Atmosphere.h>

using namespace utl;
using namespace fdet;
using namespace atm;

double
FTimeFitModel::GetTimeAtAperture(const double t0, const double rp, const double chi0,
                                 const double chi_i, const double thetaSDP, const int eye, const int tel) const
{

  switch (fModel) {

    case eRealisticAtm:
    case eRealisticAtmNoDeex:
      {
        const Atmosphere& theAtmosphere  =
          det::Detector::GetInstance().GetAtmosphere();


        const Point& telposition =
          det::Detector::GetInstance().GetFDetector().GetEye(eye).GetTelescope(tel).GetPosition();
        const UTMPoint eyeUTM(telposition,ReferenceEllipsoid::GetWGS84());
        const double telescopeHeight = eyeUTM.GetHeight();  //height of telescope a.s.l

        const double lSDP       = rp / std::sin(chi0 - chi_i); //see Fig. 6.18 of GAP-2007-099
        const double height     = lSDP * std::sin(chi_i) * std::sin(thetaSDP); //height above telescope
        const double height_asl = height + telescopeHeight; //height above sea level
        const double sinAlpha   = height/lSDP;              //see GAP-2007-099 Fig. 6.18

        const double verticalTOF = theAtmosphere.GetVerticalTimeOfFlight(telescopeHeight,
                                                                         height_asl);

        const double showerFrontTime = t0 - rp/kSpeedOfLight/std::tan(chi0 - chi_i);

        const double propagationTime = verticalTOF/sinAlpha;

        const double lifeTime = theAtmosphere.GetDeExcitationTime(height_asl);

        return propagationTime + showerFrontTime + ((fModel == eRealisticAtm) ? lifeTime : 0.);

      }
    case eVacuumAtm:
      return t0 + rp/kSpeedOfLight *  std::tan((chi0 - chi_i) /2.);
  }

  return 0.;

}

std::string FTimeFitModel::GetModelName() const {

  switch (fModel) {

    case eRealisticAtm:
      return std::string("realistic speed of light");
      break;
    case eVacuumAtm:
      return std::string("vacuum speed of light");
      break;
    default:
      return std::string("unknown");
      break;

  }
}