The GroundWinds Lidar on the north slope of Mauna Loa employs spectral line profiling of incoherent background 355 nm laser light. Very rapid measurements of the Doppler shift (400 ns resolution) is accomplished by feeding the returned laser light into a combination of two fabry-perot etalons and collapsing the interference fringes into a 1-dimensional interference pattern using a conical optic as shown in the figure below.
 

The Yag laser is pulsed at 10 Hz and each pulse is stretched to 50 ns; the average power dissipated is 5 W.

Each measurement takes 10s. The molecular return is strong up to 15 km altitude. The outgoing beam is expanded to match the fiels of view of the telescope.