Visibility is an important parameter within aviation, harbour and road monitoring applications. In the past this was a parameter which was manually observed and broadcasted to users.

Although this method is still applied, many Automatic Weather Station (AWS) are provided with a visibility sensor. Forward and backward scatter principles are quite common, while transmission meters are often used for airfield applications. Many aviation authorities nowadays also accept the use of forward scattering sensors. Observator Instruments has chosen the use of the Biral-range for these kinds of measurement. Their visibility sensor has proven to be accurate and long-lasting within marine environments, while the present weather can be determined at the same time.