Giannetti Filippo, Reggiannini Ruggero, Moretti Marco, Adirosi Elisa, Baldini Luca, Facheris Luca, Antonini Andrea, Melani Samantha, Bacci Giacomo, Petrolino Antonio, Vaccaro Attilio
Dipartimento di Ingegneria dell'Informazione, University of Pisa, Pisa 56122, Italy.
CNIT-Laboratorio Nazionale di Radar e Sistemi di Sorveglianza, Pisa 56124, Italy.
Sensors (Basel). 2017 Aug 12;17(8):1864. doi: 10.3390/s17081864.
We present the NEFOCAST project (named by the contraction of "Nefele", which is the Italian spelling for the mythological cloud nymph Nephele, and "forecast"), funded by the Tuscany Region, about the feasibility of a system for the detection and monitoring of precipitation fields over the regional territory based on the use of a widespread network of new-generation Eutelsat "SmartLNB" (smart low-noise block converter) domestic terminals. Though primarily intended for interactive satellite services, these devices can also be used as weather sensors, as they have the capability of measuring the rain-induced attenuation incurred by the downlink signal and relaying it on an auxiliary return channel. We illustrate the NEFOCAST system architecture, consisting of the network of ground sensor terminals, the space segment, and the service center, which has the task of processing the information relayed by the terminals for generating rain field maps. We discuss a few methods that allow the conversion of a rain attenuation measurement into an instantaneous rainfall rate. Specifically, we discuss an exponential model relating the specific rain attenuation to the rainfall rate, whose coefficients were obtained from extensive experimental data. The above model permits the inferring of the rainfall rate from the total signal attenuation provided by the SmartLNB and from the link geometry knowledge. Some preliminary results obtained from a SmartLNB installed in Pisa are presented and compared with the output of a conventional tipping bucket rain gauge. It is shown that the NEFOCAST sensor is able to track the fast-varying rainfall rate accurately with no delay, as opposed to a conventional gauge.
我们展示了由托斯卡纳大区资助的NEFOCAST项目（由“Nefele”的缩写命名，“Nefele”是神话中云仙女涅斐勒的意大利语拼写，以及“forecast”），该项目关于基于使用新一代欧洲通信卫星公司的“SmartLNB”（智能低噪声块下变频器）家用终端的广泛网络来检测和监测区域领土上降水场的系统的可行性。尽管这些设备主要用于交互式卫星服务，但它们也可以用作气象传感器，因为它们有能力测量下行链路信号因降雨引起的衰减，并通过辅助回传信道进行转发。我们阐述了NEFOCAST系统架构，它由地面传感器终端网络、空间段和服务中心组成，服务中心负责处理终端转发的信息以生成雨场地图。我们讨论了几种将降雨衰减测量转换为瞬时降雨率的方法。具体来说，我们讨论了一个将特定降雨衰减与降雨率相关联的指数模型，其系数是从大量实验数据中获得的。上述模型允许根据SmartLNB提供的总信号衰减以及链路几何知识推断降雨率。展示了从安装在比萨的一个SmartLNB获得的一些初步结果，并与传统翻斗式雨量计的输出进行了比较。结果表明，与传统雨量计不同，NEFOCAST传感器能够准确无误地跟踪快速变化的降雨率。
