Quantitative precipitation estimation and rainfall monitoring based on meteorological data, potentially provides continuous, high-resolution and large-coverage data, are of high practical use: Think of hydrogeological risk management, hydroelectric power, road and tourism. Both conventional long-range radars and rain-gauges suffer from measurement errors and difficulties in precipitation estimation. For efficient monitoring operation of localized rain events of limited extension and of small basins of interest, an unrealistic extremely dense rain gauge network should be needed. Alternatively C-band or S-band meteorological long range radars are able to monitor rain fields over wide areas, however with not enough space and time resolution, and with high purchase and maintenance costs. Short-range X-band radars for rain monitoring can be a valid compromise solution between the two more common rain measurement and observation instruments. Lots of scientific efforts have already focused on radar-gauge adjustment and quantitative precipitation estimation in order to improve the radar measurement techniques. After some considerations about long range radars and gauge network, this paper presents instead some examples of how X-band mini radars can be very useful for the observation of rainfall events and how they can integrate and supplement long range radars and rain gauge networks. Three case studies are presented: A very localized and intense event, a rainfall event with high temporal and spatial variability and the employ of X-band mini radar in a mountainous region with narrow valleys. The adaptability of such radar devoted to monitor rain is demonstrated.

In recent years Wireless Sensor Networks (WSNs) have attracted an increasing attention because of the large number of potential applications. They are used for collecting, storing and sharing data, for monitoring application, surveillance purposes and much more. Taking into account such multipurpose applications, a new experimental electronic board has been designed to be used specifically as a multipurpose WSN node. The board has been completely designed as an open system in order to be configured by only varying the firmware on the microcontroller to be connected with different types of sensors, such as, for example, solid state tri-axial accelerometer, analog temperature sensors, GNSS receivers, etc… The board allow different interfaces and is equipped with a recovery system via a watchdog chip which continuously monitor the onboard microcontroller. A free open source operative system has been ported on the microcontroller in order to give greater flexibility to the node, and to perform multi tasking operations. Low power consumptions together with its compact size, and its multiple functionalities made the board perfectly suited as a multipurpose WSN node. The boards have been already employed in two installed WSN: a GPS monitoring network and an WSN designed as anti-theft alarm system for photovoltaic panels.

This article depicts the development and test of a low cost wireless sensor network intended for use in severe environmental conditions. The test site is a serac located at 4100m above a populated area. It was needed to put in place a monitoring system able to trace displacement continuously and in all weather conditions. To achieve this goal starting from a professional but cheap single frequency GNSS module we developed the needed electronics to control it, log the data and transmit them over a long distance. The final board is working at 2.4 GHz and the network protocol is based on a proprietary implementation of a listen before talk approach. The high DGPS precision is obtained by using local GNSS permanent stations.

The monitoring of power consumption has become of a great interest in recent years as well as the innovative technologies available to realize Wireless Sensor Networks (WSNs) have experienced a great growth. While smart metering technologies for electric energy are already established, as sensors power supply comes directly from power lines, WSN nodes for gas metering should necessarily be equipped with long life batteries. The presented work describes a new prototypal low cost WSN designed ad hoc for gas smart metering. The network has a star topology: each sensor node can be completely integrated with standard reed relay gas meter, and it is capable to measure the gas consumption. The information is sent to the central node (the Access Point, AP) through an RF links. The sensor nodes have been designed with custom electronics and a proprietary firmware, in order to work with a common 3.6 V lithium battery which is able to ensure a life period of about 10 years for each node. Only the AP must be connected directly to electric power. The AP is connected through the RS-232 interface to a control embedded PC equipped with a LAMP (Linux, Apache, MySQL, PHP) framework: it stores all the information coming from each node in a coherent database and allows authorized users to check the network status using a web interface. The WSN is self-learning and it is capable to detect new nodes joining the network without altering the normal operative flow. Moreover e-mail and SMS alerts can be activated to alert if a node is disconnected from the network or some problems occur. A first prototype of the WSN has been already tested achieving good results.

Photovoltaic (PV) systems have attracted increasing attention in last years as well as Wireless Sensor Networks (WSNs), which have been used in many application fields. In PV plants, especially in ground installations, a lot of thefts and damages occur due to the still high cost of the modules. A new experimental WSN ad-hoc has been designed to be an anti-theft alarm system. Each node of the network is directly installed under each PV string and it is equipped with an accelerometer sensor capable to detect a minimum displacement of the panel from its steady position. The WSN presents a star topology: a master node cyclically interrogates the slave nodes through RF link. It collects all the nodes responses and communicates though a RS-232 interface with a control PC checking the network status. When a slave node detects an alarm, continuous messages are sent to the control PC which turns on all the alarm signaling systems. The control PC is equipped with an open source operative system and software and provides for SMS, e-mail and sound-light signaling in case of alarm. It also communicates with a remote server where all the WSN information is stored. A first low cost experimental WSN has been already installed and it is working properly