What is Doppler LIDAR?

The acronym "LIDAR" stands for light detection and ranging. Where radar uses radio waves to determine an object’s range or distance, LIDAR uses light in the form of a laser for a variety of measurements. Using either pulsating or continuous laser beams to measure the changes in light frequency and other factors, LIDAR laser technology serves in a variety of applications. Specifically, Doppler LIDAR measures wind speed with both pulsing and continuous laser beams. By measuring how the frequency of the laser’s light shifts, scientists and meteorologists can determine wind speed and other associated data.

Both Doppler radar and Doppler LIDAR are useful tools for determining weather conditions. For example, a scanning Doppler wind LIDAR, known as the Harlie LIDAR, can be used to measure wind velocity at the atmospheric level. The Olympic yacht competition in 2008 employed Doppler LIDAR laser technology to measure wind fields. Meteorologists for the Olympic tournament used mobile equipment supplied by Chinese researchers to help provide up-to-the-minute information on wind conditions, speed and direction.

With Doppler LIDAR technology and equipment, scientists, researchers and meteorologists send out a laser at a predetermined, set frequency. The frequency shifts as the light from the laser collides with various molecules and aerosols in the air. When the light returns to the receiver, changes in the light frequency help scientists determine specific factors such as velocity and direction. Images display on a monitor with high spatial and temporal resolution.

Research and refinement of Doppler LIDAR has continued. Such technology is slated for use in weather forecasting, military applications and aviation. Having such targeted and clear imaging of wind conditions provides a wealth of information necessary to public safety. Administrators will use the data provided about wind speed to plan public safety during severe weather conditions. Aviation and military agencies will use the technology to determine flight conditions long before crews or equipment take flight.