Sensors for Monitoring Present Weather Conditions

light from the volume which comes from falling precipitation particles or from fog or mist. Individual particles give rise to short bursts of light at the detector and fog or mist gives a more uniform increase in measured light over time. The main drawback of these scatter based instruments is lack of accuracy in measuring individual particle parameters, such as the size or velocity, especially if precipitation particles fall obliquely through the beam or have differing scattering characteristics. This means that identifying what type of precipitation is falling through the volume is usually not possible without the integration of other sensors to measure temperature or the wetness of falling particles. Since particles are not accurately measured, standard meteorological sensor outputs such as rain rates and accumulation cannot be given with any accuracy and classification of precipitation into types such as light rain or moderate drizzle is unavoidably poor.