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How do lidars and acoustic sounders study the lower atmosphere?

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Weather forecasting Doppler radars, such as this one operated by the U.S. National Weather Service at New Underwood, South Dakota, extract the Doppler frequency shift of the echo produced by a moving target by noting how much the frequency of the received signal differs from the frequency of the signal that was transmitted.

Lidars and acoustic sounders (often called sodars) are active remote sensing systems used to monitor the lower atmosphere by emitting energy and recording its reflection.1

Lidars

Lidar, which stands for light detection and ranging, utilizes laser technology to measure backscattered light. In meteorological applications, carbon dioxide lidars are specifically used to estimate wind structure and turbulence within a few tens of kilometres of the instrument. By transmitting light pulses and measuring the time taken for the signal to return, these systems provide precise data on atmospheric characteristics.12

Acoustic Sounders

Acoustic sounders, or sodars (sound detecting and ranging), function similarly to radar but use acoustic energy rather than electromagnetic waves. They are primarily employed to monitor the depth and structure of the planetary boundary layer by analyzing the characteristics of echo returns.13

Both systems are essential for studying the lower atmosphere, providing critical data that complements other measurement platforms like radiosondes and Doppler radars.1