What is attenuation?
Attenuation is the weakening of a radar beam as it moves downstream due to some of the energy being lost to scattering and absorption. The further a radar beam moves downstream the more dust, hydrometeors, etc the radar beam will have to pass through. Because of attenuation, storms close to the radar are better sampled than storms far from the radar site. Beam spreading and attenuation both combine to produce a much poorer sampling of storms far from the radar. Attenuation is higher when the radar beam has the flow through a large number of hydrometeors. Storms and precipitation close to the radar degrade the radar energy before it reaches storms further from the radar. Smaller wavelength radar beams attenuate more rapidly than long wavelength radar. Because of this, most television station radars (C-band) have a shorter range of high clarity compared to the WSR-88D radar (S-band).
A signal traveling on a cable becomes weaker the further it travels. Each interconnection also reduces its strength. At some point the signal becomes too weak for the network hardware to interpret reliably. Particularly at higher frequencies (10MHz and up) UTP cable attenuates signals much sooner than does coaxial or shielded twisted pair cable. Attenuation is the weakening (or loss) of signal strength. Knowing the attenuation (and NEXT) of a link allows you to determine whether it will function for a particular access method, and how much margin is available to accommodate increased losses due to temperature changes, aging, etc.
Related Questions
- Does TRAP binding to nascent trp leader RNA influence transcription attenuation beyond its effects on RNA structure?
- On a network analyzer, what happens to the two-port calibration if the source or receiver attenuation is changed?
- Why are mobile/portable analytical systems needed for natural attenuation studies?
