Monitoring EMI and the radio spectrum in Europe Titus Spoelstra CRAF

Monitoring Before starting: What is the question you want to answer? (avoid collection of large amounts of data) Harmonize data format and analysis tools to ease exchange of information Monitoring spectrum occupancy is not EMI/RFI monitoring

Electromagnetic Interference (EMI) The effect of unwanted energy due to one or a combination of emissions, radiations, or inductions upon reception in a radiocommunication system, or loss of information which could be extracted in the absence of such unwanted energy

Electromagnetic Interference (EMI) EMI: ‘quantification’ of degradation of the quality of an observation due to unwanted emissions, radiations, or inductions upon reception in a radiocommunication system Information about EMI is obtained by inspection of observations

Spectrum occupancy Spectrum occupancy information identifies the chance to become victim of interference This info is e.g. a scheduling tool to avoid EMI Monitoring spectrum occupancy done by dedicated instruments

RAS Monitoring facilities in Europe Half a dozen of EVN stations operate facilities to monitor spectrum occupancy In addition several radio astronomy observatories have their own specific facilities (e.g. omni- directional antenna with receiver – fixed or mobile facility) Information usually kept in house: “all data are stored”

CRAF database for EMI and spectrum occupancy Facility for all European radio astronomy stations managed by the CRAF clearing house in Dwingeloo and accessible via CRAF website Dataflow in ‘CRAF data-format’ to Dwingeloo Range of analysis tools for both EMI and spectrum occupancy

CRAF EMI Database Query Facility Query options to the CRAF EMI database: (select item by clicking on the option or BACK to previous page) BACK Interference intensity as a function of time of the day Interference intensity as a function of days of the week Interference intensity as a function of frequency Development of interference intensity as a function of time Observation degradation as a function of time of the day Observation degradation as a function of days of the week Observation degradation as a function of frequency Development of observation degradation as a function of time Interference occurrence as a function of time of the day Interference occurrence as a function of days of the week Interference occurrence as a function of frequency Development of interference occurrence as a function of time Last modified: August 8, 2001

CRAF SPECTRUM OCCUPANCY Database Query Facility Query options to the CRAF SPECTRUM OCCUPANCY database: (select item by clicking on the option or BACK to previous page) BACK Signal intensity as a function of time of the day Signal intensity as a function of days of the week Signal intensity as a function of frequency Development of signal intensity as a function of time Signal occurrence as a function of time of the day Signal occurrence as a function of days of the week Signal occurrence as a function of frequency Development of signal occurrence as a function of time Last modified: August 8, 2001

Use of information Quantified evidence for Administrations in case of trouble. NOTE: if interference is not reported to Administrations, interference does not exist! Monitor the development of the EMI “climatology” (relevant in communication with Administrations). Improve observation conditions at the station Specific projects: e.g. development of interference-robust receivers, interference suppression techniques

CRAF facility Username and password required, because: In many countries it is strictly forbidden to monitor spectrum occupancy or to ‘publish’ monitoring data.

National developments In some countries increased Administrative monitoring effort The Netherlands: cooperation between Administration and RAS on exchange of information

CEPT Stations: several for terrestrial services; for satellite monitoring: Leeheim (Germany) Improvement of monitoring effort in Europe: - MoU between CEPT Administrations - Further development of German Leeheim Satellite monitoring station into European satellite monitoring facility funded by CEPT countries