SOUSY

Principle of measurement

Both radars transmit pulses that are backscattered by variations in the atmospheric refractive index and then received. The variations in the refractive index are due to turbulent flucuations in temperature and humidity (troposphere and stratosphere) or concentrations of free electrons (mesosphere). The different origins of the refractive index variations, in turn, result in radar echoes received from two height regimes: 1 - 30 km and 60 - 90 km. The mesospheric echoes strongly depend on the time of day and season. Utilizing the Doppler shifts, the radar can measure three-dimensional velocity vectors provided the main transmitting and receiving beams are cycled through at least three non-coplanar orientations.