diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1a14268..2cc871a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -23,9 +23,12 @@ endif()
 
 enable_testing()
 
+include_directories(".")
+
 add_subdirectory(src/gui)
 add_subdirectory(src/sim)
 add_subdirectory(src/Utils)
+add_subdirectory(src/Utils/math)
 add_subdirectory(src/model)
 
 #find_package(wxWidgets REQUIRED gl core base)
diff --git a/src/Utils/math/CMakeLists.txt b/src/Utils/math/CMakeLists.txt
new file mode 100644
index 0000000..6156c19
--- /dev/null
+++ b/src/Utils/math/CMakeLists.txt
@@ -0,0 +1,3 @@
+add_library(math
+   Constants.cpp)
+
diff --git a/src/Utils/math/Constants.cpp b/src/Utils/math/Constants.cpp
new file mode 100644
index 0000000..bb08b1d
--- /dev/null
+++ b/src/Utils/math/Constants.cpp
@@ -0,0 +1 @@
+#include "Constants.h"
\ No newline at end of file
diff --git a/src/Utils/math/Constants.h b/src/Utils/math/Constants.h
index 40b3250..e92fd1c 100644
--- a/src/Utils/math/Constants.h
+++ b/src/Utils/math/Constants.h
@@ -4,12 +4,12 @@
 namespace utils::math
 {
 
-struct Constants
+namespace Constants
 {
-   static const double Rstar = 8.3144598;
-   static const double g0 = 9.80665;
-   static const double airMolarMass = 0.0289644;
-   static const double standardTemperature = 288.15;
+   constexpr double Rstar = 8.3144598;
+   constexpr const double g0 = 9.80665;
+   constexpr const double airMolarMass = 0.0289644;
+   constexpr const double standardTemperature = 288.15;
 };
 
 } // namespace utils::math
diff --git a/src/sim/CMakeLists.txt b/src/sim/CMakeLists.txt
index cdb8487..72bb603 100644
--- a/src/sim/CMakeLists.txt
+++ b/src/sim/CMakeLists.txt
@@ -1,5 +1,6 @@
 add_library(sim
    AtmosphericModel.cpp
    GravityModel.cpp
-   WindModel.cpp)
+   WindModel.cpp
+   USStandardAtmosphere.cpp)