Event Identification & Recording for Scintillation Monitoring Stations James T. Curran, Michele Bavaro, Aiden Morrison † & Joaquim Fortuny Institute for the Protection and Security of the Citizen, Joint Research Centre, Ispra (VA), Italy. † SINTEF Information and Communication Technology department, Trondheim, Norway. james.curran@, michele.bavaro@, joaquim.fortuny-guasch@jrc.ec.europa.eu, aiden.morrison@sintef.no BIOGRAPHIES James T. Curran received a B.E. in Electrical & Electronic Engineering in 2006 and a Ph.D. in Telecommunications in 2010, from the Department of Electrical Engineering, University College Cork, Ireland. He worked as a senior research engineer with the PLAN Group in the University of Calgary from 2011 and is currently a grant-holder at the Joint Research Center (JRC) of the European Commission (EC), Italy. His main research interests are signal processing, information theory, cryptography and software defined radio for GNSS. Michele Bavaro received his master degree in Computer Science in 2003 from the University of Pisa. Shortly afterwards he started his work on Software Defined Radio technologies applied to navigation. First in Italy, then in The Netherlands and in the UK he worked on several projects being directly involved with the design, manufacture, integration, and test of RNSS equipment and supporting customers in the development of their applications. Today he is appointed as grant-holder at the EC JRC. Aiden Morrison received a B. Eng. in Electrical Engineering in 2006, and a Ph.D. in Geomatics in 2010, from the University of Calgary. He has since worked as a designer of RF and navigation systems at the University of Calgary, Norbit group, and is currently employed at the SINTEF research institute in Trondheim, Norway . Joaquim Fortuny-Guasch received the Engineering degree in telecommunications from the Technical University of Catalonia (UPC), Barcelona, Spain, in 1988, and the Dr.- Ing. degree in electrical engineering from the Universität Karlsruhe (TH), Karlsruhe, Germany, in 2001. Since 1993, he has been working for the Joint Research Centre (JRC) of the European Commission, Ispra, Italy, as senior scientific officer. He is the head of the European Microwave Signature Laboratory and leads the JRC research group on GNSS and wireless communications systems. ABSTRACT This paper presents the development and deployment of a network of GNSS-based ionosphere monitoring stations. To simultaneously satisfy the requirements of traditional ionosphere monitoring via scintillation indices; and to support the collection of digital IF samples, suitable for atmospheric research and receiver development, a custom software-defined radio platform has been developed. Owing to the high data throughput associated with the collection of IF data various means of reducing the storage requirements are explored. These include the tradeoff between both IF bandwidth and digitizer resolution and the associate fidelity of scintillation measurements; the real-time identification of scintillation events, whereby only those recordings of short periods of interest are archived. The process is considered as three distinct tasks, those of: data acquisition, run-time event identification, and post-mission event analysis. The design, configuration and run-time calibration of the data acquisition unit are discussed; a heuristic event detection method, based on a software-defined GNSS receiver is described and preliminary results obtained from some scintillation event analysis are presented. INTRODUCTION Ionospheric scintillation typically has adverse effects on the synchronization and tracking stage of a GNSS receiver and poses a threat to all navigation receives including stand-alone, differential, assisted and inertial- coupled receivers [1]. As such, monitoring the ionosphere via GNSS signals is an important task, both to understand space weather and the atmosphere and to understand its effects on GNSS receiver operation and performance [2,3]. GNSS-based studies of the ionosphere are typically conducted using navigation receivers which track both the carrier and code phase either on a satellite-by-satellite basis, or collectively via a vector structure [2]. Information relating to phase and amplitude scintillation is gathered from the receiver’s estimate of the carrier phase and the receiver correlator values, respectively. While monitoring stations of this kind have been widely deployed, and continuously harvest valuable information, they are limited in their application to receiver design. Efforts have been made to apply this gathered amplitude and phase information to the testing of commercial receivers. Notably, this has been done in the form of applying measured scintillation events to simulated signals [4,5]. The capture of intermediate-frequency (IF) data is another powerful approach, and allows post- processing by software defined receivers and, in some cases, conductive rebroadcast to commercial receivers [6,7]. Indeed, this has been demonstrated as being an effective way of analyzing and comparing receiver performance [6,7]. The capture of raw IF, however, poses some significant challenges. Unlike signal observations,