Keywords: IncidentAngle-NPS.gif en Diagram of a ray showing the incident angle and refraction in the F layer This ray that is at a lower frequency than the F layer MUF but higher than the E layer MUF http //www weather nps navy mil/~psguest/EMEO_online/module3/module_3_2b html Naval Postgraduate School 1/12/2004 http //www nps navy mil/NPS/Disclaimers htm PD-USGov Ionosphere Radio propagation |