Category: Radio Navigation

In this post, we shall understand about Ionospheric Attenuation and Refraction. We had learnt about Refraction of Radio Waves in our previous post. Ionospheric layer is found in the upper levels of stratosphere in atmosphere. Ionosphere consists of negatively charged free electrons due to ionized gasses. Ionisation is the process of ejecting electrons from an atom. Radio Waves which travel to ionosphere are refracted as well as attenuated in the ionosphere. Ionospheric attenuation causes loss of energy in the radio wave due to collisions between wave particles and free electrons…

Refraction results in bending of radio waves while passing from one medium to another. On the other hand, we had learnt earlier that diffraction refers to the bending of radio waves around obstacles. The speed of radio waves is 3×108 Meters/Second2 only when it s being transmitted through vacuum. In all other mediums, their speed varies depending on the medium of transmission. This change in velocity of radio waves results in change of their direction when radio waves transit through from one medium to another with varying densities. This process…

Diffraction of radio waves occur due to the bending of Radio Waves when they encounter obstacles in their transmission path. In our earlier post, we had learnt about Atmospheric, Reflection and Static Attenuation. Diffraction refers to the property of radio waves which enables them to bend or spread around obstacles. In the context of radio navigation it refers to bending of Radio Waves around the surface of earth. Higher diffraction is seen in lower frequencies like VLF, LF and HF bands. These radio waves bend around the earth’s surface and…