radar frequency band—A frequency band of microwave radiation within which radars operate. The radar frequency bands were first designated by code letters for secrecy during World War II; these letters are still in common use, although the exact frequency intervals to which they apply have undergone some redefinition.
They all fall within the UHF, SHF, and EHF radio frequency bands. The bands normally used for radar detection of precipitation and clouds are the following.
Radars operating in the S, C, and X bands are the ones mainly used for precipitation measurements. Attenuation of the transmitted radio frequency energy by atmospheric gases, precipitation, and cloud particles is severe for all frequency bands higher than X band, and even X band can suffer severe attenuation in heavy rain. Nevertheless, because radars operating in the K, Ka, and W bands are able to detect clouds, they are used for cloud observations even though they are not able to penetrate far through precipitation. Radar wind profilers and MST radars operate at lower frequencies than those included in this table, namely, in the UHF and VHF bands. Compare radio frequency band.