Woodman Pollitt, Ronald Francisco2018-07-132018-07-132002-12http://hdl.handle.net/20.500.12816/1807En: Encyclopedia of Atmospheric Sciences, edited by James R. Holton et al., Academic Press, 2002, p. 1825-1832.To qualify as an MST radar, the system has to be capable of obtaining echoes from the mesosphere. This requirement limits the frequency range of these radars to the lower frequencies of the VHF band, i.e., between 30 and 300 MHz. Smaller radars, using the same principles and techniques but capable of reaching only the stratosphere and troposphere, are called ST radars. Here we can cite as an example the NOAA Tropical Pacific Profiler Network in the equatorial Pacific, and the wind profiler network in central United States as important multiple radar installations that qualify as such. These, and even smaller systems capable of observing only the troposphere, are also called wind profilers, because of their main use as operacional radars dedicated to measuring the winds aloft in a continuous manner. At these lower altitudes it is possible to use frequencies higher than VHF frequencies. Nowadays, many radars designed for other purposes, including operational air traffic, meteorological Doppler radars, and ionospheric incoherent­scatter radars, are also used as ST radars.application/pdfenginfo:eu-repo/semantics/openAccessIncoherent scattering radarRadarWindsIonosphereAtmosphereinfo:eu-repo/semantics/bookParthttp://purl.org/pe-repo/ocde/ford#1.05.01