Daily Archives: March 18, 2024

The weather observing stations of the National Weather Service operate in fully automatic mode and have sensors that measure visibility.

These instruments sense the forward scattering characteristics of light to measure the extinction coefficient of a high intensity beam directed at a volume of air close to the sensor. This provides an accurate measurement over a range of visibilities. The use of light within the visible spectrum also allows the sensor to simulate human perception of visibility. Continue reading →