.. _program_listing_file_agents_constellation.cc:

Program Listing for File constellation.cc
=========================================

|exhale_lsh| :ref:`Return to documentation for file <file_agents_constellation.cc>` (``agents/constellation.cc``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   #include "lupnt/agents/constellation.h"
   
   #include <regex>
   
   #include "lupnt/agents/satellite.h"
   #include "lupnt/conversions/state_conversions.h"
   #include "lupnt/devices/comms.h"
   #include "lupnt/dynamics/numerical_orbit_dynamics.h"
   #include "lupnt/states/state.h"
   #include "lupnt/states/tle.h"
   
   namespace lupnt {
   
     Constellation::Constellation() {}
   
     Constellation::Constellation(Config& config) {
       auto tle_name = config["tle"].as<std::string>();
       name_ = config["name"].as<std::string>();
       for (auto tle : TLE::FromFile(tle_name)) {
         // Classical Orbital Elements
         Real T = SECS_DAY / tle.mean_motion;
         Real a = pow((T * T * GM_EARTH) / (4.0 * PI * PI), 1.0 / 3.0);
         Real e = tle.eccentricity;
         Real i = tle.inclination * RAD;
         Real Omega = tle.raan * RAD;
         Real w = tle.arg_perigee * RAD;
         Real rad_per_sec = tle.mean_motion * 2 * PI / SECS_DAY;
         Real dt = GetLupntEpoch() - tle.epoch_tai;
         Real M = WrapToPi(tle.mean_anomaly * RAD + rad_per_sec * dt);
   
         // State and Dynamics
         State coe = ClassicalOE({a, e, i, Omega, w, M}, Frame::GCRF);
         State rv = ClassicalToCart(coe, GM_EARTH);
         auto dyn = MakePtr<CartesianTwoBodyDynamics>(GM_EARTH);
         Config attitude_config(config["attitude_dynamics"]);
         auto attitude_dyn = MakePtr<FixedPointingDynamics>(attitude_config);
         Real frequency = config["frequency"].as<Real>();
         std::string name = name_ + "/" + std::regex_replace(tle.name, std::regex(" "), "_");
   
         // Devices
         auto gnss_transmitter = MakePtr<Transmitter>();
         gnss_transmitter->SetName(name + "/gnss_transmitter");
   
         // Satellite
         auto sat = MakePtr<Satellite>();
         sat->SetTime(0.0);
         sat->SetState(rv);
         sat->SetAttitude(Attitude(Vec4(1.0, 0.0, 0.0, 0.0), Vec3(0.0, 0.0, 0.0), Frame::GCRF));
         sat->SetName(name);
         sat->SetFrequency(frequency);
         sat->SetDynamics(std::move(dyn));
         sat->AddDevice(std::move(gnss_transmitter));
         sat->SetAttitudeDynamics(std::move(attitude_dyn));
   
         satellites_.push_back(std::move(sat));
       }
     }
   
     void Constellation::Setup() {
       for (auto& sat : satellites_) sat->Setup();
     }
   
     void Constellation::Step(Real time) {
       for (auto& sat : satellites_) sat->Step(time);
     }
   
     void Constellation::SetSimulation(Simulation* sim) {
       sim_ = sim;
       for (auto& sat : satellites_) sat->SetSimulation(sim);
     }
   
   }  // namespace lupnt