Forward scatter sensor

A forward scatter sensor for precipitation analysis, the forward scatter sensor comprising:

• a transmitter arranged to emit a single light sheet that has a height that is small in comparison to its width and that has a substantially uniform height both in lateral direction and along its propagation path, wherein light energy distribution is substantially uniform in the lateral direction of the single light sheet;
• a receiver offset from a propagation path of the single light sheet and arranged to observe light scattered from particles that fall through a measurement volume defined by an intersection of the propagation path of the single light sheet and a field of view of the receiver;
• and
• a control entity comprising an analyzer arranged to record a measurement signal that is descriptive of intensity of light captured by the receiver as a function of time, wherein the analyzer is arranged to carry out a precipitation analysis on basis of a time segment of the measurement signal, the precipitation analysis comprising:
• identifying, in said time segment of the measurement signal, one or more double peaks that each represent a respective droplet and comprise a first peak that represents light refracted from a bottom of the respective droplet upon entry to the measurement volume and a second peak that represents light reflected from a top of the respective droplet upon exit from the measurement volume;
• deriving one or more precipitation parameters based at least in part on the identified one or more double peaks, wherein said one or more precipitation parameters comprise one or more of the following:
• a number of precipitation particles, respective sizes of the precipitation particles, respective falling speeds of the precipitation particles, and respective types of the precipitation particles;
• and
• deriving one or more precipitation indications based at least in part on the derived one or more precipitation parameters, wherein the precipitation indications comprise one or more of the following:
• an indication of presence of precipitation, an indication of precipitation type, an indication of precipitation intensity, an indication of accumulated precipitation, an indication of liquid water content, and precipitation particle size distribution.