Abstract: An example forward scatter sensor comprises: a transmitter arranged to emit a single light sheet; a receiver to observe light scattered from particles that fall through a measurement volume; and a control entity comprising an analyzer arranged to record a measurement signal descriptive of intensity of light captured by the receiver as a function of time and 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, 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; and deriving one or more precipitation parameters and one or more precipitation indications.

Abstract: An example forward scatter sensor comprises: a transmitter to emit a light sheet; a receiver to observe light scattered from particles that fall through a measurement volume; and a control entity comprising an analyzer to record a measurement signal descriptive of intensity of light captured by the receiver as a function of time and to: carry out a precipitation analysis on basis of a time segment of the measurement signal; 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; and invoke a predefined maintenance action responsive 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.

Abstract: An example forward scatter sensor comprises: a transmitter to emit a light sheet; a receiver to observe light scattered from particles that fall through a measurement volume; and a control entity comprising an analyzer to record a measurement signal descriptive of intensity of light captured by the receiver as a function of time and to: carry out a precipitation analysis on basis of a time segment of the measurement signal; 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; and invoke a predefined maintenance action responsive 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.

Abstract: An example forward scatter sensor comprises: a transmitter arranged to emit a single light sheet; a receiver to observe light scattered from particles that fall through a measurement volume; and a control entity comprising an analyzer arranged to record a measurement signal descriptive of intensity of light captured by the receiver as a function of time and 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, 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; and deriving one or more precipitation parameters and one or more precipitation indications.

Abstract: The invention relates to a precipitation detector (1) and method for measurement of precipitation parameters. The detector (1) includes a frame (5), a surface (2) mounted on the frame (5) and adapted to receive hydrometeors, and detection means (3) for converting the impact impulses of hydrometeors into an electric signal. According to the invention, the surface (2) receiving the impact of the hydrometeors is convex, stiff and rigidly connected to the detector frame (4) with the detection means (3) being permanently connected to the surface (2) receiving the impact of the hydrometeors.

Abstract: The invention relates to an apparatus and method for measuring visibility and present weather. The apparatus includes a light source (1) for directing a light ray toward the object (9) to be measured, a detector (3) for measurement of light which is forward scattered from the object (9), and computing elements (12-15) adapted to differentiate the signal representing the forward scattered light from signals representing stray or ambient light. The apparatus may include a pulsed light source, a receiver (19) for receiving directly backward reflected/scattered light pulses, and computing elements (11) for computing the propagation delays of the different backward reflected components in the received pulse-shaped optical signal.

Abstract: The invention concerns a method and device for measuring the meteorological visibility and the scattering of light. A light pulse is emitted into the atmosphere via an optical transmit system, the backscattered light returns via the optical transmit system after which its intensity and delay are measured. The waveform of the optical transmit pulse generated at the instant of its launching from within the apparatus is sensed in a manner that excludes any backscattered light originating from outside the measurement system, this signal is scaled for both its magnitude and phase so as to achieve a suitable feedback signal relative to the actual measurement signal and said feedback signal is subtracted from said measurement signal to avoid overloading of the receiver.