By digitizing the points at which each detector picks up a single wave, a computer can measure time and separation. It then can compute the average velocity of a massive column of air crossing the laser beam. In this case, wind speed calculations were made every 10 seconds. The sensor correlated extremely well with anemometer readings in test results with 100 feet between the sensor and the target. A five percent discrepancy, within the limits of experimental error, was observed between wind speed measurements by the sensor and by the anemometer in laboratory tests.
Companies often rely on anemometers to check wind direction and velocity.
The cost of this sensor would be less than that of one meteorological tower. The sensor is easier to use than Doppler systems, the researchers say. In addition, it measures wind across the beam of light instead of along the beam, as Doppler systems do. It operates well in sunlight and in darkness. Like many optical systems, the sensor doesn't work as well in rain or fog, which obscure its target.