It seems there are many scientific laser ranging stations around the globe and some are mobile.
Scientists Bounce Laser Off Soviet Lunar Rover Lost On Moon Decades Ago. Source
- How dangerous are those scientific laser beams for passengers and crew, and for the aircraft?
- Is there a NOTAM or a temporary flight restriction associated with scientific laser activity?
In satellite laser ranging (SLR) a global network of observation stations measures the round trip time of flight of ultrashort pulses of light to satellites equipped with retroreflectors. This provides instantaneous range measurements of millimeter level precision which can be accumulated to provide accurate measurement of orbits and a host of important scientific data.
International Laser Ranging Service - Map of stations. Source.
and for the Moon:
Laser beams are used because they remain tightly focused for large distances. Nevertheless, there is enough dispersion of the beam that it is about 7 kilometers in diameter when it reaches the Moon and 20 kilometers in diameter when it returns to Earth. Because of this very weak signal, observations are made for several hours at a time. By averaging the signal for this period, the distance to the Moon can be measured to an accuracy of about 3 centimeters.
For astrophysics purposes:
Adaptive optics systems require a wavefront reference source in order to correct atmospheric distortion of light. Sufficiently bright stars are not available in all parts of the sky [...], one can create an artificial guide star by shining a laser into the atmosphere.
- Thanks to Federico, a very nice timelapse video of laser activity at Mauna Kea (by Sean Goebel).