A FORWARD SCATTER SENSOR

According to an example embodiment, a forward scatter sensor for precipitation analysis is provided, the forward scatter sensor comprising: a transmitter arranged to emit a light sheet; a receiver offset from a propagation path of the 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 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 further arranged to: carry out a precipitation analysis on basis of a time segment of the measurement signal, the 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 the bottom of the respective droplet upon entry to the measurement volume and a second peak that represents light reflected from the top of the respective droplet upon exit from the measurement volume; carry out a verification of analysis performance based on magnitudes of first peaks of at least one identified double peak and on respective residence times for said at least one identified double peak, wherein the residence time for a given double peak is defined by a time difference between the first and second peaks of the given double peak; and invoke a predefined maintenance action in response to said verification indicating a threshold-exceeding difference between respective size estimates derived based on magnitudes of the first peak of said at least one identified double peak and based on residence times of said at least one identified double peak.