Laser radar (LIDAR) is a radar that uses light
in place of the radio-frequency signals used in conventional radar.
Advantage of laser radar include its potential for very
high azimuthal resolution. Disadvantages include its sensitivity to dust and
smoke.
One popular application of the laser radar is to
make hydrographic measurements from aircraft, where the use of two
different frequencies allow simultaneous measurement of the distance from the
aircraft to the water's surface and to the sea bottom.
This use of laser radar to measure sea depth
is known as Lidar Bathymetry.