The purpose of the experimental activity of MOPRAM is the comparison between the precipitation estimates retrieved by commercial microwave links (CML) and that one measured by conventional instruments (rain gauges and dysdrometers).

We chose an area of ​​hydrogeological interest and we collect the rain data by rain gauges and microwave links moreover we installed new sensors (dysdrometers).


One of the case studies analyzed by MOPRAM is the catchment area of ​​the Mallero torrent in the province of Sondrio. It is situated in the Valmalenco, a valley that opens orthogonally to Valtellina the whole height of Sondrio, and then develops in a northern direction between the western Rhaetian Alps. Valmalenco is generally characterized by an alpine climate due to its geographical position and its purely mountainous character.

The hydrological regime of the Mallero is torrential and is influenced by several factors. Being the mountain basin, the snow melt and the glacial melt have a strong impact on the flow rates measured in Sondrio. The contribution of glacial melting is not negligible as glaciers cover a total of 10% of the entire Mallero basin. In addition, the Mallero torrent is subject to variations in flow rate due to significant withdrawals by the hydroelectric plants present in the valley.


In the area there are 19 microwave radio links that can be used as opportunistic rain sensors as there is a relationship, by single connection, between the intensity of the precipitation along the link and the attenuation of the radio signal.

Rainfall calculated from radio links has been compared with that measured by more conventional instruments such as rain gauges and dysdrometers.

The rain gauges provide measurements of total precipitation height, solid and liquid, in mm of water equivalent. In the area there are 13 rain gauges.

In addition to the rain gauge measurements, the MOPRAM project also installed 3 disdrometers.

The disdrometer is an instrument designed to simultaneously provide the measurement of the diameters and the falling speeds of the hydrometeors that pass through a laser matrix. Furthermore, it is able to distinguish the type of precipitation (hail, rain ..)


MOPRAM carried out a measurement campaign in Valmalenco for the installation of 3 disdrometers. The disdrometers have been installed in correspondence with microwave links, to compare in the same point the rain measured by the gauge and that obtained by the microwave links.

The dysdrometer mini pc is connected in real time with our offices at the Politecnico di Milano, from which you can access and monitor the functioning of the instrument.

One of the dysdrometers is located in the splendid setting of the Orobie Valtellinesi Park, with which a collaboration activity has begun.

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