Exploring new solutions for remote sensing and environmental monitoring

The Remote Sensing Group (RSG, www.remotesensinggroup.polito.it) of Politecnico di Torino is also the local research unit of CINFAI (Consorzio Interuniversitario Nazionale per la Fisica delle Atmosfere e delle Idrosfere, www.cinfai.it) within the DET (Department of Electronics and Telecommunications). Its activities are devoted to explore new solutions ranging from radar meteorology, to the realization of innovative sensing probes, from Wireless Sensor Network (WSN) and RFID tags realization (in order to measure environmental parameters, even deploying them in harsh environment), to the application of commercial technologies in innovative contexts. Within these topics four different activities are presented. The first activity is the realization of a prototype of an X-band FMICW (Frequency Modulated Interrupted Continuous Wave) which was developed for atmospheric monitoring operations (e.g. for rainfall estimation). Its main characteristics are the low cost and the complete software programmability. First results show a good resolution and consistent rain estimation within a range of 3 km. The second topic is related to the feasibility analysis made to study a set of innovative disposable sensors for atmosphere and precipitation studies. While most monitoring instruments for the atmosphere perform indirect monitoring operation, sensing the parameters from a remote position and not being directly inside the phenomenon, the proposed sensors (very small and light, it weighs less than 15 g) are designed to dynamically behave like hailstones or raindrops in their fluctuations and falling through the atmosphere. During the flight time they can measure atmospheric parameters and send them to a receiver located on the ground. The third presented solution is the realization of a RFID tags-reader system capable to work in very harsh operative conditions. The ad-hoc system was designed to monitor several physical properties of glaciers, the prototype was realized and tested on filed with very good results. The system is made up of a set of RFID tags placed directly inside the ice to perform the measurements and a handheld reader (equipped also with a custom software) to collect data according to user needs. The last activity explores the use of the frequency band of 77 GHz for short range weather radar or a microwave rain gauge. According to ETSI (European Telecommunications Standards Institute) such frequency band is dedicated to automatic cruise control long-range radars. Recent studies, including some results presented here, show that is possible to use FMCW radar commonly used to enable a vehicle to maintain a cruising distance from the preceding vehicle as radar for meteorology purposes, with small modifications. The crucial derivation of the relation between the radar reflectivity factor Z [mm6m-3] and rainfall rate R [mm/h] (usually known as “Z-R equation” or “Marshall and Palmer” equation) is necessary in order to prevent heavy underestimation of rain. Some early results obtained with numerical techniques are presented.