diff --git a/src/dynamics/orbit/encke_orbit_propagation.cpp b/src/dynamics/orbit/encke_orbit_propagation.cpp
index a5a839d5c..9b67322f2 100644
--- a/src/dynamics/orbit/encke_orbit_propagation.cpp
+++ b/src/dynamics/orbit/encke_orbit_propagation.cpp
@@ -90,8 +90,8 @@ void EnckeOrbitPropagation::Initialize(double current_time_jd, math::Vector<3> r
   // reference orbit
   reference_position_i_m_ = reference_position_i_m;
   reference_velocity_i_m_s_ = reference_velocity_i_m_s;
-  OrbitalElements oe_ref(gravity_constant_m3_s2_, current_time_jd, reference_position_i_m, reference_velocity_i_m_s);
-  reference_kepler_orbit = KeplerOrbit(gravity_constant_m3_s2_, oe_ref);
+  orbit::OrbitalElements oe_ref(gravity_constant_m3_s2_, current_time_jd, reference_position_i_m, reference_velocity_i_m_s);
+  reference_kepler_orbit = orbit::KeplerOrbit(gravity_constant_m3_s2_, oe_ref);
 
   // difference orbit
   difference_position_i_m_.FillUp(0.0);
diff --git a/src/dynamics/orbit/encke_orbit_propagation.hpp b/src/dynamics/orbit/encke_orbit_propagation.hpp
index a6abce7e8..a32052e2b 100644
--- a/src/dynamics/orbit/encke_orbit_propagation.hpp
+++ b/src/dynamics/orbit/encke_orbit_propagation.hpp
@@ -65,7 +65,7 @@ class EnckeOrbitPropagation : public Orbit, public math::OrdinaryDifferentialEqu
   // reference orbit
   math::Vector<3> reference_position_i_m_;    //!< Reference orbit position in the inertial frame [m]
   math::Vector<3> reference_velocity_i_m_s_;  //!< Reference orbit velocity in the inertial frame [m/s]
-  KeplerOrbit reference_kepler_orbit;         //!< Reference Kepler orbital element
+  orbit::KeplerOrbit reference_kepler_orbit;  //!< Reference Kepler orbital element
 
   // difference orbit
   math::Vector<3> difference_position_i_m_;    //!< Difference orbit position in the inertial frame [m]
diff --git a/src/dynamics/orbit/initialize_orbit.cpp b/src/dynamics/orbit/initialize_orbit.cpp
index 9921da134..8ce7ab313 100644
--- a/src/dynamics/orbit/initialize_orbit.cpp
+++ b/src/dynamics/orbit/initialize_orbit.cpp
@@ -46,8 +46,8 @@ Orbit* InitOrbit(const CelestialInformation* celestial_information, std::string
     // initialize orbit for relative dynamics of formation flying
     RelativeOrbit::RelativeOrbitUpdateMethod update_method =
         (RelativeOrbit::RelativeOrbitUpdateMethod)(conf.ReadInt(section_, "relative_orbit_update_method"));
-    RelativeOrbitModel relative_dynamics_model_type = (RelativeOrbitModel)(conf.ReadInt(section_, "relative_dynamics_model_type"));
-    StmModel stm_model_type = (StmModel)(conf.ReadInt(section_, "stm_model_type"));
+    orbit::RelativeOrbitModel relative_dynamics_model_type = (orbit::RelativeOrbitModel)(conf.ReadInt(section_, "relative_dynamics_model_type"));
+    orbit::StmModel stm_model_type = (orbit::StmModel)(conf.ReadInt(section_, "stm_model_type"));
 
     math::Vector<3> init_relative_position_lvlh;
     conf.ReadVector<3>(section_, "initial_relative_position_lvlh_m", init_relative_position_lvlh);
@@ -62,7 +62,7 @@ Orbit* InitOrbit(const CelestialInformation* celestial_information, std::string
                               init_relative_velocity_lvlh, update_method, relative_dynamics_model_type, stm_model_type, relative_information);
   } else if (propagate_mode == "KEPLER") {
     // initialize orbit for Kepler propagation
-    OrbitalElements oe;
+    orbit::OrbitalElements oe;
     // TODO: init_mode_kepler should be removed in the next major update
     if (initialize_mode == OrbitInitializeMode::kInertialPositionAndVelocity) {
       // initialize with position and velocity
@@ -70,7 +70,7 @@ Orbit* InitOrbit(const CelestialInformation* celestial_information, std::string
       conf.ReadVector<3>(section_, "initial_position_i_m", init_pos_m);
       math::Vector<3> init_vel_m_s;
       conf.ReadVector<3>(section_, "initial_velocity_i_m_s", init_vel_m_s);
-      oe = OrbitalElements(gravity_constant_m3_s2, current_time_jd, init_pos_m, init_vel_m_s);
+      oe = orbit::OrbitalElements(gravity_constant_m3_s2, current_time_jd, init_pos_m, init_vel_m_s);
     } else {
       // initialize with orbital elements
       double semi_major_axis_m = conf.ReadDouble(section_, "semi_major_axis_m");
@@ -79,9 +79,9 @@ Orbit* InitOrbit(const CelestialInformation* celestial_information, std::string
       double raan_rad = conf.ReadDouble(section_, "raan_rad");
       double arg_perigee_rad = conf.ReadDouble(section_, "argument_of_perigee_rad");
       double epoch_jday = conf.ReadDouble(section_, "epoch_jday");
-      oe = OrbitalElements(epoch_jday, semi_major_axis_m, eccentricity, inclination_rad, raan_rad, arg_perigee_rad);
+      oe = orbit::OrbitalElements(epoch_jday, semi_major_axis_m, eccentricity, inclination_rad, raan_rad, arg_perigee_rad);
     }
-    KeplerOrbit kepler_orbit(gravity_constant_m3_s2, oe);
+    orbit::KeplerOrbit kepler_orbit(gravity_constant_m3_s2, oe);
     orbit = new KeplerOrbitPropagation(celestial_information, current_time_jd, kepler_orbit);
   } else if (propagate_mode == "ENCKE") {
     // initialize orbit for Encke's method
@@ -130,8 +130,8 @@ math::Vector<6> InitializePosVel(std::string initialize_file, double current_tim
     double raan_rad = conf.ReadDouble(section_, "raan_rad");
     double arg_perigee_rad = conf.ReadDouble(section_, "argument_of_perigee_rad");
     double epoch_jday = conf.ReadDouble(section_, "epoch_jday");
-    OrbitalElements oe(epoch_jday, semi_major_axis_m, eccentricity, inclination_rad, raan_rad, arg_perigee_rad);
-    KeplerOrbit kepler_orbit(gravity_constant_m3_s2, oe);
+    orbit::OrbitalElements oe(epoch_jday, semi_major_axis_m, eccentricity, inclination_rad, raan_rad, arg_perigee_rad);
+    orbit::KeplerOrbit kepler_orbit(gravity_constant_m3_s2, oe);
 
     kepler_orbit.CalcOrbit(current_time_jd);
     position_i_m = kepler_orbit.GetPosition_i_m();
diff --git a/src/dynamics/orbit/kepler_orbit_propagation.hpp b/src/dynamics/orbit/kepler_orbit_propagation.hpp
index f2421003e..ec93197ab 100644
--- a/src/dynamics/orbit/kepler_orbit_propagation.hpp
+++ b/src/dynamics/orbit/kepler_orbit_propagation.hpp
@@ -13,7 +13,7 @@
  * @class KeplerOrbitPropagation
  * @brief Class to propagate spacecraft orbit with Kepler equation
  */
-class KeplerOrbitPropagation : public Orbit, public KeplerOrbit {
+class KeplerOrbitPropagation : public Orbit, public orbit::KeplerOrbit {
  public:
   // Initialize with orbital elements
   /**
@@ -23,7 +23,7 @@ class KeplerOrbitPropagation : public Orbit, public KeplerOrbit {
    * @param [in] current_time_jd: Current Julian day [day]
    * @param [in] kepler_orbit: Kepler orbit
    */
-  KeplerOrbitPropagation(const CelestialInformation* celestial_information, const double current_time_jd, KeplerOrbit kepler_orbit);
+  KeplerOrbitPropagation(const CelestialInformation* celestial_information, const double current_time_jd, orbit::KeplerOrbit kepler_orbit);
   /**
    * @fn ~KeplerOrbitPropagation
    * @brief Destructor
diff --git a/src/dynamics/orbit/relative_orbit.cpp b/src/dynamics/orbit/relative_orbit.cpp
index 5bf3270e3..f60f52682 100644
--- a/src/dynamics/orbit/relative_orbit.cpp
+++ b/src/dynamics/orbit/relative_orbit.cpp
@@ -10,8 +10,8 @@
 
 RelativeOrbit::RelativeOrbit(const CelestialInformation* celestial_information, double gravity_constant_m3_s2, double time_step_s,
                              int reference_spacecraft_id, math::Vector<3> relative_position_lvlh_m, math::Vector<3> relative_velocity_lvlh_m_s,
-                             RelativeOrbitUpdateMethod update_method, RelativeOrbitModel relative_dynamics_model_type, StmModel stm_model_type,
-                             RelativeInformation* relative_information)
+                             RelativeOrbitUpdateMethod update_method, orbit::RelativeOrbitModel relative_dynamics_model_type,
+                             orbit::StmModel stm_model_type, RelativeInformation* relative_information)
     : Orbit(celestial_information),
       math::OrdinaryDifferentialEquation<6>(time_step_s),
       gravity_constant_m3_s2_(gravity_constant_m3_s2),
@@ -66,12 +66,12 @@ void RelativeOrbit::InitializeState(math::Vector<3> relative_position_lvlh_m, ma
   TransformEcefToGeodetic();
 }
 
-void RelativeOrbit::CalculateSystemMatrix(RelativeOrbitModel relative_dynamics_model_type, const Orbit* reference_sat_orbit,
+void RelativeOrbit::CalculateSystemMatrix(orbit::RelativeOrbitModel relative_dynamics_model_type, const Orbit* reference_sat_orbit,
                                           double gravity_constant_m3_s2) {
   switch (relative_dynamics_model_type) {
-    case RelativeOrbitModel::kHill: {
+    case orbit::RelativeOrbitModel::kHill: {
       double reference_sat_orbit_radius = reference_sat_orbit->GetPosition_i_m().CalcNorm();
-      system_matrix_ = CalcHillSystemMatrix(reference_sat_orbit_radius, gravity_constant_m3_s2);
+      system_matrix_ = orbit::CalcHillSystemMatrix(reference_sat_orbit_radius, gravity_constant_m3_s2);
     }
     default: {
       // NOT REACHED
@@ -80,11 +80,12 @@ void RelativeOrbit::CalculateSystemMatrix(RelativeOrbitModel relative_dynamics_m
   }
 }
 
-void RelativeOrbit::CalculateStm(StmModel stm_model_type, const Orbit* reference_sat_orbit, double gravity_constant_m3_s2, double elapsed_sec) {
+void RelativeOrbit::CalculateStm(orbit::StmModel stm_model_type, const Orbit* reference_sat_orbit, double gravity_constant_m3_s2,
+                                 double elapsed_sec) {
   switch (stm_model_type) {
-    case StmModel::kHcw: {
+    case orbit::StmModel::kHcw: {
       double reference_sat_orbit_radius = reference_sat_orbit->GetPosition_i_m().CalcNorm();
-      stm_ = CalcHcwStm(reference_sat_orbit_radius, gravity_constant_m3_s2, elapsed_sec);
+      stm_ = orbit::CalcHcwStm(reference_sat_orbit_radius, gravity_constant_m3_s2, elapsed_sec);
     }
     default: {
       // NOT REACHED
diff --git a/src/dynamics/orbit/relative_orbit.hpp b/src/dynamics/orbit/relative_orbit.hpp
index 82560566c..3aae6e104 100644
--- a/src/dynamics/orbit/relative_orbit.hpp
+++ b/src/dynamics/orbit/relative_orbit.hpp
@@ -41,7 +41,7 @@ class RelativeOrbit : public Orbit, public math::OrdinaryDifferentialEquation<6>
    */
   RelativeOrbit(const CelestialInformation* celestial_information, double gravity_constant_m3_s2, double time_step_s, int reference_spacecraft_id,
                 math::Vector<3> relative_position_lvlh_m, math::Vector<3> relative_velocity_lvlh_m_s, RelativeOrbitUpdateMethod update_method,
-                RelativeOrbitModel relative_dynamics_model_type, StmModel stm_model_type, RelativeInformation* relative_information);
+                orbit::RelativeOrbitModel relative_dynamics_model_type, orbit::StmModel stm_model_type, RelativeInformation* relative_information);
   /**
    * @fn ~RelativeOrbit
    * @brief Destructor
@@ -80,10 +80,10 @@ class RelativeOrbit : public Orbit, public math::OrdinaryDifferentialEquation<6>
   math::Vector<3> relative_position_lvlh_m_;    //!< Relative position in the LVLH frame
   math::Vector<3> relative_velocity_lvlh_m_s_;  //!< Relative velocity in the LVLH frame
 
-  RelativeOrbitUpdateMethod update_method_;          //!< Update method
-  RelativeOrbitModel relative_dynamics_model_type_;  //!< Relative dynamics model type
-  StmModel stm_model_type_;                          //!< State Transition Matrix model type
-  RelativeInformation* relative_information_;        //!< Relative information
+  RelativeOrbitUpdateMethod update_method_;                 //!< Update method
+  orbit::RelativeOrbitModel relative_dynamics_model_type_;  //!< Relative dynamics model type
+  orbit::StmModel stm_model_type_;                          //!< State Transition Matrix model type
+  RelativeInformation* relative_information_;               //!< Relative information
 
   /**
    * @fn InitializeState
@@ -102,7 +102,7 @@ class RelativeOrbit : public Orbit, public math::OrdinaryDifferentialEquation<6>
    * @param [in] reference_sat_orbit: Orbit information of reference satellite
    * @param [in] gravity_constant_m3_s2: Gravity constant of the center body [m3/s2]
    */
-  void CalculateSystemMatrix(RelativeOrbitModel relative_dynamics_model_type, const Orbit* reference_sat_orbit, double gravity_constant_m3_s2);
+  void CalculateSystemMatrix(orbit::RelativeOrbitModel relative_dynamics_model_type, const Orbit* reference_sat_orbit, double gravity_constant_m3_s2);
   /**
    * @fn CalculateStm
    * @brief Calculate State Transition Matrix
@@ -111,7 +111,7 @@ class RelativeOrbit : public Orbit, public math::OrdinaryDifferentialEquation<6>
    * @param [in] gravity_constant_m3_s2: Gravity constant of the center body [m3/s2]
    * @param [in] elapsed_sec: Elapsed time [sec]
    */
-  void CalculateStm(StmModel stm_model_type, const Orbit* reference_sat_orbit, double gravity_constant_m3_s2, double elapsed_sec);
+  void CalculateStm(orbit::StmModel stm_model_type, const Orbit* reference_sat_orbit, double gravity_constant_m3_s2, double elapsed_sec);
   /**
    * @fn PropagateRk4
    * @brief Propagate relative orbit with RK4
diff --git a/src/environment/global/gnss_satellites.cpp b/src/environment/global/gnss_satellites.cpp
index d68216ea2..c3af068f2 100644
--- a/src/environment/global/gnss_satellites.cpp
+++ b/src/environment/global/gnss_satellites.cpp
@@ -15,6 +15,8 @@
 #include "setting_file_reader/initialize_file_access.hpp"
 #include "utilities/macros.hpp"
 
+using namespace gnss;
+
 const size_t kNumberOfInterpolation = 9;
 
 void GnssSatellites::Initialize(const std::vector<Sp3FileReader>& sp3_files, const EpochTime start_time) {
@@ -38,7 +40,7 @@ void GnssSatellites::Initialize(const std::vector<Sp3FileReader>& sp3_files, con
   reference_time_ = EpochTime(initial_sp3_file.GetEpochData(reference_interpolation_id_));
 
   // Initialize orbit
-  orbit_.assign(number_of_calculated_gnss_satellites_, InterpolationOrbit(kNumberOfInterpolation));
+  orbit_.assign(number_of_calculated_gnss_satellites_, orbit::InterpolationOrbit(kNumberOfInterpolation));
 
   // Initialize clock
   std::vector<double> temp;
diff --git a/src/environment/global/gnss_satellites.hpp b/src/environment/global/gnss_satellites.hpp
index a3021e64c..0aa46ef38 100644
--- a/src/environment/global/gnss_satellites.hpp
+++ b/src/environment/global/gnss_satellites.hpp
@@ -54,7 +54,7 @@ class GnssSatellites : public ILoggable {
    * @param [in] sp3_files: List of SP3 files
    * @param [in] start_time: The simulation start time
    */
-  void Initialize(const std::vector<Sp3FileReader>& sp3_files, const EpochTime start_time);
+  void Initialize(const std::vector<gnss::Sp3FileReader>& sp3_files, const EpochTime start_time);
 
   /**
    * @fn IsCalcEnabled
@@ -113,15 +113,15 @@ class GnssSatellites : public ILoggable {
  private:
   bool is_calc_enabled_ = false;  //!< Flag to manage the GNSS satellite position calculation
 
-  std::vector<Sp3FileReader> sp3_files_;         //!< List of SP3 files
+  std::vector<gnss::Sp3FileReader> sp3_files_;   //!< List of SP3 files
   size_t number_of_calculated_gnss_satellites_;  //!< Number of calculated GNSS satellites
   size_t sp3_file_id_;                           //!< Current SP3 file ID
   EpochTime reference_time_;                     //!< Reference start time of the SP3 handling
   size_t reference_interpolation_id_ = 0;        //!< Reference epoch ID of the interpolation
   EpochTime current_epoch_time_;                 //!< The last updated time
 
-  std::vector<InterpolationOrbit> orbit_;   //!< GNSS satellite orbit with interpolation
-  std::vector<math::Interpolation> clock_;  //!< GNSS satellite clock offset with interpolation
+  std::vector<orbit::InterpolationOrbit> orbit_;  //!< GNSS satellite orbit with interpolation
+  std::vector<math::Interpolation> clock_;        //!< GNSS satellite clock offset with interpolation
 
   // References
   const EarthRotation& earth_rotation_;  //!< Earth rotation
@@ -133,7 +133,7 @@ class GnssSatellites : public ILoggable {
    * @param [in] current_time: Target time
    * @return true means no error, false means the time argument is out of range
    */
-  bool GetCurrentSp3File(Sp3FileReader& current_sp3_file, const EpochTime current_time);
+  bool GetCurrentSp3File(gnss::Sp3FileReader& current_sp3_file, const EpochTime current_time);
 
   /**
    * @fn UpdateInterpolationInformation
diff --git a/src/math_physics/gnss/antex_file_reader.cpp b/src/math_physics/gnss/antex_file_reader.cpp
index e9c379787..1547a3cf4 100644
--- a/src/math_physics/gnss/antex_file_reader.cpp
+++ b/src/math_physics/gnss/antex_file_reader.cpp
@@ -10,6 +10,8 @@
 #include <iostream>
 #include <math_physics/gnss/gnss_satellite_number.hpp>
 
+namespace gnss {
+
 #define ANTEX_LINE_TYPE_POSITION (60)
 
 AntexGridDefinition::AntexGridDefinition(const double zenith_start_angle_deg, const double zenith_end_angle_deg, const double zenith_step_angle_deg,
@@ -196,3 +198,5 @@ DateTime AntexFileReader::ReadDateTime(std::string line) {
   sscanf(line.c_str(), "%zu %2zu %2zu %2zu %2zu %10lf", &year, &month, &day, &hour, &minute, &second);
   return DateTime(year, month, day, hour, minute, second);
 }
+
+}  // namespace gnss
diff --git a/src/math_physics/gnss/antex_file_reader.hpp b/src/math_physics/gnss/antex_file_reader.hpp
index ef2ef64c4..e730b09c2 100644
--- a/src/math_physics/gnss/antex_file_reader.hpp
+++ b/src/math_physics/gnss/antex_file_reader.hpp
@@ -16,6 +16,8 @@
 #include <string>
 #include <vector>
 
+namespace gnss {
+
 /**
  * @class AntexGridDefinition
  * @brief grid data definition in ANTEX file
@@ -343,4 +345,6 @@ class AntexFileReader {
   DateTime ReadDateTime(std::string line);
 };
 
+}  // namespace gnss
+
 #endif  // S2E_LIBRARY_ANTEX_FILE_READER_HPP_
diff --git a/src/math_physics/gnss/bias_sinex_file_reader.cpp b/src/math_physics/gnss/bias_sinex_file_reader.cpp
index ebb47913a..252523ebf 100644
--- a/src/math_physics/gnss/bias_sinex_file_reader.cpp
+++ b/src/math_physics/gnss/bias_sinex_file_reader.cpp
@@ -9,6 +9,8 @@
 #include <fstream>
 #include <iostream>
 
+namespace gnss {
+
 bool BiasSinexFileReader::ReadFile(const std::string file_name) {
   // File open
   std::ifstream bias_sinex_file(file_name);
@@ -242,3 +244,5 @@ void BiasSolutionData::SetTargetSignal(const std::string signal1, const std::str
     target_signal_ = BiasTargetSignal::kError;
   }
 }
+
+}  // namespace gnss
diff --git a/src/math_physics/gnss/bias_sinex_file_reader.hpp b/src/math_physics/gnss/bias_sinex_file_reader.hpp
index 49d85e91e..20e591d0c 100644
--- a/src/math_physics/gnss/bias_sinex_file_reader.hpp
+++ b/src/math_physics/gnss/bias_sinex_file_reader.hpp
@@ -10,6 +10,8 @@
 #include <string>
 #include <vector>
 
+namespace gnss {
+
 /**
  * @enum BiasIdentifier
  * @brief Bias Identifier
@@ -184,4 +186,6 @@ class BiasSinexFileReader {
   void ReadBiasSolution(std::ifstream& bias_sinex_file);
 };
 
+}  // namespace gnss
+
 #endif  // S2E_LIBRARY_BIAS_SINEX_FILE_READER_HPP_
\ No newline at end of file
diff --git a/src/math_physics/gnss/gnss_satellite_number.cpp b/src/math_physics/gnss/gnss_satellite_number.cpp
index b3c53efba..6eb8861a5 100644
--- a/src/math_physics/gnss/gnss_satellite_number.cpp
+++ b/src/math_physics/gnss/gnss_satellite_number.cpp
@@ -5,6 +5,8 @@
 
 #include "gnss_satellite_number.hpp"
 
+namespace gnss {
+
 size_t ConvertGnssSatelliteNumberToIndex(const std::string satellite_number) {
   switch (satellite_number.front()) {
     case 'G':
@@ -58,3 +60,5 @@ std::string ConvertIndexToGnssSatelliteNumber(const size_t index) {
 
   return output;
 }
+
+}  // namespace gnss
diff --git a/src/math_physics/gnss/gnss_satellite_number.hpp b/src/math_physics/gnss/gnss_satellite_number.hpp
index 08fd91576..35087c537 100644
--- a/src/math_physics/gnss/gnss_satellite_number.hpp
+++ b/src/math_physics/gnss/gnss_satellite_number.hpp
@@ -10,6 +10,8 @@
 
 #include <string>
 
+namespace gnss {
+
 // GNSS satellite number definition
 // TODO: Move to initialized file?
 const size_t kNumberOfGpsSatellite = 32;      //!< Number of GPS satellites
@@ -44,4 +46,6 @@ size_t ConvertGnssSatelliteNumberToIndex(const std::string satellite_number);
  */
 std::string ConvertIndexToGnssSatelliteNumber(const size_t index);
 
+}  // namespace gnss
+
 #endif  // S2E_LIBRARY_GNSS_GNSS_SATELLITE_NUMBER_HPP_
diff --git a/src/math_physics/gnss/igs_product_name_handling.hpp b/src/math_physics/gnss/igs_product_name_handling.hpp
index 7f2644e8d..e2352f76c 100644
--- a/src/math_physics/gnss/igs_product_name_handling.hpp
+++ b/src/math_physics/gnss/igs_product_name_handling.hpp
@@ -10,6 +10,8 @@
 
 #include <string>
 
+namespace gnss {
+
 /**
  * @fn GetOrbitClockFileName
  * @brief Return IGS orbit and clock final product file name
@@ -83,4 +85,6 @@ size_t IncrementYearDoy(const size_t year_doy) {
   return output;
 }
 
+}  // namespace gnss
+
 #endif  // S2E_LIBRARY_GNSS_IGS_PRODUCT_NAME_HANDLING_HPP_
diff --git a/src/math_physics/gnss/sp3_file_reader.cpp b/src/math_physics/gnss/sp3_file_reader.cpp
index 10043e10d..8106ba9cc 100644
--- a/src/math_physics/gnss/sp3_file_reader.cpp
+++ b/src/math_physics/gnss/sp3_file_reader.cpp
@@ -11,6 +11,8 @@
 #include <fstream>
 #include <iostream>
 
+namespace gnss {
+
 Sp3FileReader::Sp3FileReader(const std::string file_name) { ReadFile(file_name); }
 
 DateTime Sp3FileReader::GetEpochData(const size_t epoch_id) const {
@@ -419,3 +421,5 @@ Sp3VelocityClockRateCorrelation Sp3FileReader::DecodeVelocityClockRateCorrelatio
 
   return correlation;
 }
+
+}  // namespace gnss
diff --git a/src/math_physics/gnss/sp3_file_reader.hpp b/src/math_physics/gnss/sp3_file_reader.hpp
index 4b7a017eb..e904b6050 100644
--- a/src/math_physics/gnss/sp3_file_reader.hpp
+++ b/src/math_physics/gnss/sp3_file_reader.hpp
@@ -17,6 +17,8 @@
 #include <string>
 #include <vector>
 
+namespace gnss {
+
 #define SP3_BAD_CLOCK_VALUE (999999.999999)
 #define SP3_BAD_POSITION_VALUE (0.000000)
 
@@ -234,4 +236,6 @@ class Sp3FileReader {
   Sp3VelocityClockRateCorrelation DecodeVelocityClockRateCorrelation(std::string line);
 };
 
+}  // namespace gnss
+
 #endif  // S2E_LIBRARY_GNSS_SP3_FILE_READER_HPP_
diff --git a/src/math_physics/gnss/test_antex_file_reader.cpp b/src/math_physics/gnss/test_antex_file_reader.cpp
index d5d392f19..320c598af 100644
--- a/src/math_physics/gnss/test_antex_file_reader.cpp
+++ b/src/math_physics/gnss/test_antex_file_reader.cpp
@@ -7,6 +7,8 @@
 
 #include "antex_file_reader.hpp"
 
+using namespace gnss;
+
 /**
  * @brief Test Constructor
  */
diff --git a/src/math_physics/gnss/test_bias_sinex_file_reader.cpp b/src/math_physics/gnss/test_bias_sinex_file_reader.cpp
index 99c52c8d7..a681eedcc 100644
--- a/src/math_physics/gnss/test_bias_sinex_file_reader.cpp
+++ b/src/math_physics/gnss/test_bias_sinex_file_reader.cpp
@@ -2,6 +2,8 @@
 
 #include "bias_sinex_file_reader.hpp"
 
+using namespace gnss;
+
 TEST(BiasSinex, Constructor) {
   // File read error check
   BiasSinexFileReader bias_sinex_file_fault("false_file_path.BSX");
diff --git a/src/math_physics/gnss/test_gnss_satellite_number.cpp b/src/math_physics/gnss/test_gnss_satellite_number.cpp
index 5bbf535ee..259920e29 100644
--- a/src/math_physics/gnss/test_gnss_satellite_number.cpp
+++ b/src/math_physics/gnss/test_gnss_satellite_number.cpp
@@ -6,6 +6,8 @@
 
 #include "gnss_satellite_number.hpp"
 
+using namespace gnss;
+
 /**
  * @brief Test satellite number to index
  */
diff --git a/src/math_physics/gnss/test_igs_product_name_handling.cpp b/src/math_physics/gnss/test_igs_product_name_handling.cpp
index b674af7dc..f1af19529 100644
--- a/src/math_physics/gnss/test_igs_product_name_handling.cpp
+++ b/src/math_physics/gnss/test_igs_product_name_handling.cpp
@@ -7,6 +7,8 @@
 
 #include "igs_product_name_handling.hpp"
 
+using namespace gnss;
+
 /**
  * @brief Test GetOrbitClockFinalFileName
  */
diff --git a/src/math_physics/gnss/test_sp3_file_reader.cpp b/src/math_physics/gnss/test_sp3_file_reader.cpp
index 4a017894e..9ef514d41 100644
--- a/src/math_physics/gnss/test_sp3_file_reader.cpp
+++ b/src/math_physics/gnss/test_sp3_file_reader.cpp
@@ -6,6 +6,8 @@
 
 #include "sp3_file_reader.hpp"
 
+using namespace gnss;
+
 /**
  * @brief Test Constructor
  */
diff --git a/src/math_physics/numerical_integration/test_runge_kutta.cpp b/src/math_physics/numerical_integration/test_runge_kutta.cpp
index fd2438ec6..376406850 100644
--- a/src/math_physics/numerical_integration/test_runge_kutta.cpp
+++ b/src/math_physics/numerical_integration/test_runge_kutta.cpp
@@ -416,8 +416,8 @@ TEST(NUMERICAL_INTEGRATION, Integrate2dTwoBodyOrbitSmallEccentricity) {
   initial_position[1] = initial_state[1];
   initial_velocity[0] = initial_state[2];
   initial_velocity[1] = initial_state[3];
-  OrbitalElements oe(1.0, 0.0, initial_position, initial_velocity);
-  KeplerOrbit kepler(1.0, oe);
+  orbit::OrbitalElements oe(1.0, 0.0, initial_position, initial_velocity);
+  orbit::KeplerOrbit kepler(1.0, oe);
   kepler.CalcOrbit((double)(step_num * step_width_s) / (24.0 * 60.0 * 60.0));
 
   double error_tolerance = 2e-4;
@@ -486,8 +486,8 @@ TEST(NUMERICAL_INTEGRATION, Integrate2dTwoBodyOrbitLargeEccentricity) {
   initial_position[1] = initial_state[1];
   initial_velocity[0] = initial_state[2];
   initial_velocity[1] = initial_state[3];
-  OrbitalElements oe(1.0, 0.0, initial_position, initial_velocity);
-  KeplerOrbit kepler(1.0, oe);
+  orbit::OrbitalElements oe(1.0, 0.0, initial_position, initial_velocity);
+  orbit::KeplerOrbit kepler(1.0, oe);
   kepler.CalcOrbit((double)(step_num * step_width_s) / (24.0 * 60.0 * 60.0));
 
   double error_tolerance = 2e-1;
@@ -551,8 +551,8 @@ TEST(NUMERICAL_INTEGRATION, Interpolation2dTwoBodyOrbitSmallEccentricity) {
   initial_position[1] = initial_state[1];
   initial_velocity[0] = initial_state[2];
   initial_velocity[1] = initial_state[3];
-  OrbitalElements oe(1.0, 0.0, initial_position, initial_velocity);
-  KeplerOrbit kepler(1.0, oe);
+  orbit::OrbitalElements oe(1.0, 0.0, initial_position, initial_velocity);
+  orbit::KeplerOrbit kepler(1.0, oe);
   kepler.CalcOrbit((double)(step_num * step_width_s) / (24.0 * 60.0 * 60.0));
 
   double error_tolerance = 5e-2;
@@ -646,8 +646,8 @@ TEST(NUMERICAL_INTEGRATION, Interpolation2dTwoBodyOrbitLargeEccentricity) {
   initial_position[1] = initial_state[1];
   initial_velocity[0] = initial_state[2];
   initial_velocity[1] = initial_state[3];
-  OrbitalElements oe(1.0, 0.0, initial_position, initial_velocity);
-  KeplerOrbit kepler(1.0, oe);
+  orbit::OrbitalElements oe(1.0, 0.0, initial_position, initial_velocity);
+  orbit::KeplerOrbit kepler(1.0, oe);
   kepler.CalcOrbit((double)(step_num * step_width_s) / (24.0 * 60.0 * 60.0));
 
   double error_tolerance = 1e-5;
diff --git a/src/math_physics/orbit/interpolation_orbit.cpp b/src/math_physics/orbit/interpolation_orbit.cpp
index c7d26302a..33d2843a5 100644
--- a/src/math_physics/orbit/interpolation_orbit.cpp
+++ b/src/math_physics/orbit/interpolation_orbit.cpp
@@ -5,6 +5,8 @@
 
 #include "interpolation_orbit.hpp"
 
+namespace orbit {
+
 InterpolationOrbit::InterpolationOrbit(const size_t degree) {
   std::vector<double> time;
   time.assign(degree, -1.0);
@@ -34,3 +36,5 @@ math::Vector<3> InterpolationOrbit::CalcPositionWithTrigonometric(const double t
   }
   return output_position;
 }
+
+}  // namespace orbit
diff --git a/src/math_physics/orbit/interpolation_orbit.hpp b/src/math_physics/orbit/interpolation_orbit.hpp
index 10a60ed6b..cf83660ab 100644
--- a/src/math_physics/orbit/interpolation_orbit.hpp
+++ b/src/math_physics/orbit/interpolation_orbit.hpp
@@ -10,6 +10,8 @@
 #include <math_physics/math/vector.hpp>
 #include <vector>
 
+namespace orbit {
+
 /**
  * @class InterpolationOrbit
  * @brief Orbit calculation with mathematical interpolation
@@ -69,4 +71,6 @@ class InterpolationOrbit {
   std::vector<math::Interpolation> interpolation_position_;  // 3D vector of interpolation
 };
 
+}  // namespace orbit
+
 #endif  // S2E_LIBRARY_ORBIT_INTERPOLATION_ORBIT_HPP_
diff --git a/src/math_physics/orbit/kepler_orbit.cpp b/src/math_physics/orbit/kepler_orbit.cpp
index ca7458152..2b3878703 100644
--- a/src/math_physics/orbit/kepler_orbit.cpp
+++ b/src/math_physics/orbit/kepler_orbit.cpp
@@ -7,6 +7,8 @@
 #include "../math/matrix_vector.hpp"
 #include "../math/s2e_math.hpp"
 
+namespace orbit {
+
 KeplerOrbit::KeplerOrbit() {}
 // Initialize with orbital elements
 KeplerOrbit::KeplerOrbit(const double gravity_constant_m3_s2, const OrbitalElements oe) : gravity_constant_m3_s2_(gravity_constant_m3_s2), oe_(oe) {
@@ -97,3 +99,5 @@ double KeplerOrbit::SolveKeplerNewtonMethod(const double eccentricity, const dou
   }
   return u_rad;
 }
+
+}  // namespace orbit
diff --git a/src/math_physics/orbit/kepler_orbit.hpp b/src/math_physics/orbit/kepler_orbit.hpp
index a19784a0d..fec55f130 100644
--- a/src/math_physics/orbit/kepler_orbit.hpp
+++ b/src/math_physics/orbit/kepler_orbit.hpp
@@ -10,6 +10,8 @@
 #include "../math/vector.hpp"
 #include "./orbital_elements.hpp"
 
+namespace orbit {
+
 /**
  * @class KeplerOrbit
  * @brief Class to calculate Kepler orbit calculation
@@ -87,4 +89,6 @@ class KeplerOrbit {
   double SolveKeplerNewtonMethod(const double eccentricity, const double mean_anomaly_rad, const double angle_limit_rad, const int iteration_limit);
 };
 
+}  // namespace orbit
+
 #endif  // S2E_LIBRARY_ORBIT_KEPLER_ORBIT_HPP_
diff --git a/src/math_physics/orbit/orbital_elements.cpp b/src/math_physics/orbit/orbital_elements.cpp
index dbd3e89d8..3fd2920b7 100644
--- a/src/math_physics/orbit/orbital_elements.cpp
+++ b/src/math_physics/orbit/orbital_elements.cpp
@@ -9,6 +9,8 @@
 
 #include "../math/s2e_math.hpp"
 
+namespace orbit {
+
 OrbitalElements::OrbitalElements() {}
 
 // initialize with OE
@@ -85,3 +87,5 @@ void OrbitalElements::CalcOeFromPosVel(const double gravity_constant_m3_s2, cons
   double dt_s = (u_rad - eccentricity_ * sin(u_rad)) / n_rad_s;
   epoch_jday_ = time_jday - dt_s / (24.0 * 60.0 * 60.0);
 }
+
+}  // namespace orbit
diff --git a/src/math_physics/orbit/orbital_elements.hpp b/src/math_physics/orbit/orbital_elements.hpp
index 9b813ac5a..27424653e 100644
--- a/src/math_physics/orbit/orbital_elements.hpp
+++ b/src/math_physics/orbit/orbital_elements.hpp
@@ -8,6 +8,8 @@
 
 #include "../math/vector.hpp"
 
+namespace orbit {
+
 /**
  * @class OrbitalElements
  * @brief Class for classical orbital elements
@@ -104,4 +106,6 @@ class OrbitalElements {
                         const math::Vector<3> velocity_i_m_s);
 };
 
+}  // namespace orbit
+
 #endif  // S2E_LIBRARY_ORBIT_ORBITAL_ELEMENTS_HPP_
diff --git a/src/math_physics/orbit/relative_orbit_models.cpp b/src/math_physics/orbit/relative_orbit_models.cpp
index e7c83ca9a..a291e4633 100644
--- a/src/math_physics/orbit/relative_orbit_models.cpp
+++ b/src/math_physics/orbit/relative_orbit_models.cpp
@@ -4,6 +4,8 @@
  */
 #include "relative_orbit_models.hpp"
 
+namespace orbit {
+
 math::Matrix<6, 6> CalcHillSystemMatrix(double orbit_radius_m, double gravity_constant_m3_s2) {
   math::Matrix<6, 6> system_matrix;
 
@@ -91,3 +93,5 @@ math::Matrix<6, 6> CalcHcwStm(double orbit_radius_m, double gravity_constant_m3_
   stm[5][5] = cos(n * t);
   return stm;
 }
+
+}  // namespace orbit
diff --git a/src/math_physics/orbit/relative_orbit_models.hpp b/src/math_physics/orbit/relative_orbit_models.hpp
index ff120823d..881d73bfb 100644
--- a/src/math_physics/orbit/relative_orbit_models.hpp
+++ b/src/math_physics/orbit/relative_orbit_models.hpp
@@ -9,6 +9,8 @@
 #include "../math/matrix.hpp"
 #include "../math/vector.hpp"
 
+namespace orbit {
+
 /**
  * @enum RelativeOrbitModel
  * @brief Relative orbit model
@@ -42,4 +44,6 @@ math::Matrix<6, 6> CalcHillSystemMatrix(const double orbit_radius_m, const doubl
  */
 math::Matrix<6, 6> CalcHcwStm(const double orbit_radius_m, const double gravity_constant_m3_s2, const double elapsed_time_s);
 
+}  // namespace orbit
+
 #endif  // S2E_LIBRARY_ORBIT_RELATIVE_ORBIT_MODEL_HPP_
diff --git a/src/math_physics/orbit/test_interpolation_orbit.cpp b/src/math_physics/orbit/test_interpolation_orbit.cpp
index 22439c87e..d7fe51c67 100644
--- a/src/math_physics/orbit/test_interpolation_orbit.cpp
+++ b/src/math_physics/orbit/test_interpolation_orbit.cpp
@@ -8,6 +8,8 @@
 
 #include "interpolation_orbit.hpp"
 
+using namespace orbit;
+
 /**
  * @brief Test for Constructor function
  */