GTODTransformations.cpp

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//
// Created by vformato on 6/27/23.
//
 
#include "Utility/FrameTransformation/GTODTransformations.h"
#include "Utility/FrameTransformation/FrameTransformations.h"
 
namespace NAIA {
namespace FrameTransformation {
PolarCoo<RefFrame::GTOD> AMSLocal_to_GTOD(float track_theta, float track_phi, const RTIInfo &rti_info) {
  // NOTE: (based on the chain of function calls in gbatch) track theta and phi refer to the particle momentum vector
  //       They are inverted in the AMS frame of reference before being converted in GTOD
  CartesianCoo<RefFrame::AMSLocal> track_direction{PolarCoo<RefFrame::AMSLocal>{1, track_theta, track_phi}};
  track_direction *= -1;
 
  PolarCoo<RefFrame::GTOD> iss_position_ang{rti_info.Altitude + RTIInfo::Re, rti_info.Theta, rti_info.Phi};
 
  PolarCoo<RefFrame::GTOD> iss_velocity_ang{rti_info.Velocity_s * iss_position_ang.R(), rti_info.Velocity_theta,
                                            rti_info.Velocity_phi};
 
  //   - ISS conversions
  //   1. Convert ISS position to cartesian
  CartesianCoo<RefFrame::GTOD> iss_position_gtod{iss_position_ang};
 
  //   2. Convert ISS velocity to cartesian
  CartesianCoo<RefFrame::GTOD> iss_velocity_gtod{iss_velocity_ang};
 
  //   3. Convert ISS GTOD coordinates and velocity to equatorial (FT_GTOD2Equat)
  CartesianCoo<RefFrame::ECI> iss_position_eci = GTODToECIPos(iss_position_gtod, rti_info.UTCTime);
  CartesianCoo<RefFrame::ECI> iss_velocity_eci = GTODToECIVel(iss_velocity_gtod, iss_position_gtod, rti_info.UTCTime);
 
  //   - AMS track coordinates conversions
  //   4. Convert AMS track coordinates to ISS-Body reference frame
  CartesianCoo<RefFrame::ISSBody> track_coo_issbody = AMSLocalToISSBody(track_direction);
 
  //   5. Convert from ISS-Body to LVLH (Local Vertical - Local Horizontal) reference frame
  CartesianCoo<RefFrame::ISSLVLH> track_coo_lvlh =
      ISSBodyToLVLH(track_coo_issbody, rti_info.Yaw, rti_info.Pitch, rti_info.Roll);
 
  //   6. Convert from ISS LVLH to ECI (Earth Centered Inertial, i.e. "equatorial") reference frame
  CartesianCoo<RefFrame::ECI> track_coo_eci = ISSLVLHToECI(track_coo_lvlh, iss_position_eci, iss_velocity_eci);
 
  //   7. Convert from equatorial to GTOD
  CartesianCoo<RefFrame::GTOD> track_coo_gtod = ECIToGTOD(track_coo_eci, rti_info.UTCTime);
 
  //   8. Compute GTOD theta and phi from cartesian coordinates
  //   9. return result
  return PolarCoo<RefFrame::GTOD>{track_coo_gtod};
}
} // namespace FrameTransformation
} // namespace NAIA