Atmospheric Attenuation

Click here to go to our main radar page

click here to go to our radar range equation page

Click here to go to our basic concepts of microwave engineering page

New for March 2019.  This content was split off from our what's the frequency page.

Atmosperhic attenuation affects radar and communications, it is your job to know how to take this into account...

Below is the classic attenuation figure that dates back to at least 1968, in Bean and Dutton's Radio Meteorology: You should be familiar with the water absorption bands at 22, 183 and 323 GHz, and the oxygen absorption regions at 60 and 118 GH, so why not print this plot out and hang it in your cube right now? These regions have higher attenuation, which is not always a bad thing, if you want your signal to die off at close distances, like for example the 4G applications (you don't want the neighbors accessing all of your wireless transmissions, do you?)

The A and B lines are for two types of weather (case A is rain). Update May 2013: Michael sent us an improved graphic which he created by hand tracing the original, which is shown below. Thanks!


Loss V Freq Air

Here the original chart, the exact origin of this fuzzy artwork is unknown.

Author : Unknown Editor