GNSS Ionospheric Activities in JRC-ISPRA

Transcription

1 GNSS Ionospheric Activities in JRC-ISPRA M. Zürn, J. Curran, M. Bavaro, J. Fortuny EC Joint Research Centre Institute for the Protection and Security of the Citizen Ispra (Italy) WMO SWx WG Meeting, Ispra, 25 Nov 2014

2 Outline 2 / 21 Background and motivation Current focus: impact assessment on GNSS Rx Performance Monitoring/IFdata Recording of ionospheric scintillation events in the Equatorial Region (PE,VN) Open-Loop Receiver Architecture Future Activities

3 Background IPSC is currently investigating the vulnerabilities of GNSS systems to: 3 / 21 anthropogenic interference sources (e.g., DBV-T, RFI, ) natural interference sources (e.g., space weather) Ground critical infrastructures are vulnerable (e.g., those relying on GNSS-based services for precise timing and synchronization) Country-wide fixed and wireless networks (i.e., internet), the power grid (PMU), banking services, stock markets (time stamping with 5 ms accuracy), and sea, air, rail and road transportation networks, PPS (oil and gas industries), precision farming, aviation,

4 JRC Testing Facilities 4

5 JRC Testing Facilities GPS and Galileo in a Room: Spirent GSS8000 hardware simulator integrated with the transmission chain of the anechoic chamber Integration with programmable signal generators for interference tests: CW Swept AM/FM LTE, WLAN DVB-T, Wimax, UWB, Rebroadcasting of signals collected by a wideband GNSS antenna on the EMSL rooftop Signal vector analyzers for collecting data in any GNSS bands (up to 6 GHz, up to 50 MHz bandwidth) Playback capabilities 5

6 Ionospheric Scintillation Monitoring in the Equatorial Region JRC Activities: started in late 2010 Development of hardware and software tools for the collection and analysis of GNSS data affected by scintillation events Jicamarca Radio Observatory (JRO) in Peru established in 1960 Located right at the Eq Anomaly Operations started at the beginning of April 2012 Availability of regular observations of the ionosphere made with the largest VHF radar in the Equatorial Region Unique facilities and know-how in Ionospheric monitoring

7 JRC Scintillation Monitoring Stations 1 st Station hosted at Peru s IGP Jicamarca Radio Observatory with: 3 control PCs, 1 GPS/L1 Rx, 1 Multi-Freq Multi-Const PRO SMR (SSN), and a USRP IF Data Grabber 2 nd Station operated in collaboration with ISMB Torino and NAVIS Center at HUST with: 1 USRP IF Data Grabber and 1 control PC - Active since Feb 13 7

8 Scintillation Monitoring Software Real-time software continuously computing the S4 and other GPS observables. Collection of IF data: triggered by anomalous S4 values (passing of S4 threshold) For each event: 20 min of IF data

9 Example Observations in GPS L1/L2/L5 at JRO on (SSN PolaRxS Pro)

10 Example Observations in GAL E1/E5a/E5b at JRO on (SSN PolaRxS Pro)

11 Example daily reports from JRO

12 Current Activities Continue the recording of IFdata sets to feed into the JRC Library of IFdata scintillation datasets (Right now > 10 TByte of IF datasets) In-depth analysis of the potentialities of OLA for scintillation receivers - Assess carefully its robustness and potential Real Time implementation Testing of Quad-Band IFdata grabber in Norway jointly with SINTEF If successful future IF datasets will be multi-freq multi-const Possible installation of additional IFdata grabbing stations

13 Scintillation Monitoring Receivers Typically measure amplitude and phase effects: S 4 and σ φ Measurement generation requires that the receiver is tracking the affected signal The quality of the measurements is influenced by how well the receiver can track the signals. Strong scintillation events can cause tracking degradation and Loss-of-Lock Aim to develop an Open-Loop Architecture for scintillation monitoring.

14 Open-Loop Architecture Feed-Forward or Open-Loop tracking of code and carrier Exploit knowledge of system-time and Rx antenna position Local carrier/code generation is independent of received signal quality Eliminates acquisition and tracking algorithms Does not suffer from cycle-slips, loss-of-lock BUT requires a good time-reference and careful signal reconstruction

15 Measurement Quality & Availabillity Amplitude Scintillation: S 4 Measurements generated in an open-loop architecture are comparable in quality to those of a SMR Open-Loop scheme may provide greater availability

16 Measurement Quality & Availabillity Phase Scintillation: σ φ Measurements generated in an open-loop architecture are comparable in quality to those of a Professional SMR Open-Loop scheme provides faster convergence

17 Quad-Band GNSS IFdata Grabber

18 Feel free to contact me: Interested? 18 / 21 J. Fortuny-Guasch Institute for the Protection and Security of the Citizen (IPSC) European Commission Joint Research Centre I Italy Joaquim.Fortuny@jrc.ec.europa.eu Acknowledgement ISMB Torino, NAVIS Group at HUST, and ESA for offering us the possibility to install the IFdata grabber at Hanoi

19 Concluding Remarks The JRC is mainly interested in assessing the impact of interference on the performance of commercial receivers Focus of the activity is on the quantitative assessment of the impact of anthropogenic and natural interference sources Facilities to carry out stress tests on commercial receivers Work is on-going to test receivers under amplitude scintillation, using signal generators and collecting raw IF datasets in the Equatorial region A massive amount of IF data collected both in Peru and Vietnam, indepth analysis of the events still on-going (~15 TByte of IF data) IF datasets might be played back repeatedly in order to assess the impact of scintillation on any available receiver 19 / 21