The Rayleigh lidar system transmits pulsed laser light into the atmosphere and receive light backscattered by atmospheric molecules. The system observes the atmospheric density and temperature profiles from the received light intensity. Rayleigh lidar is capable of measuring the vertical profile of temperature at the altitudes from 30 km to 80 km. This is one of important techniques for observing temperature profiles in this altitude range except for sounding rockets.
Rayleigh Doppler lidar is for observing atmospheric winds by measuring the spectrum of scattered light to estimate the change in its center wavelength between the original pulsed laser light and the received light caused by the Doppler shift of the motions of atmospheric molecules' drift (wind speed). This system is uniquely able to measure the wind of neutral atmosphere in the upper stratosphere and lower mesosphere.
These capabilities to measure temperatures using Rayleigh lidar and wind using Rayleigh-Doppler lidar will become the strong tools to study atmospheric waves and atmospheric circulation.