Atmospheric Ray Tracing - ODESolver

- fixed indicing bug

src/ITAPropagationPathSim/AtmosphericRayTracing/ODESolver/ODESolver.cpp

@@ -28,7 +28,7 @@ VistaVector3D WFPositionDerivative(const VistaVector3D& s, const double& omega,
 //! Calculates the derivative of the slowness vector z-component according to the ODEs for a stratified medium
 double SlownessZDerivativeStratified(const VistaVector3D& s, const double& omega, const double& c, const double& dc, const VistaVector3D& dv)
 {
-	return - ( omega / c * dc + s[1]*dv[1] + s[2]*dv[2] );
+	return - ( omega / c * dc + s[Vista::X]*dv[Vista::X] + s[Vista::Y]*dv[Vista::Y] );
 }
 
 //! Calculates the derivatives of the wavefront position and slowness vector according to the ODEs for a stratified medium