Monitoring EMI and the radio spectrum in Europe

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Monitoring EMI and the radio spectrum in Europe

• Titus Spoelstra
• CRAF

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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

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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

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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

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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

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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

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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

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CRAF EMI DatabaseQuery Facility

• Query options to the CRAF EMI database
• (select item by clicking on the option or BACK
  to previous page)
• 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

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CRAF SPECTRUM OCCUPANCY DatabaseQuery Facility

• Query options to the CRAF SPECTRUM OCCUPANCY
  database
• (select item by clicking on the option or BACK
  to previous page)
• 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

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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

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CRAF facility

• Username and password required, because
• In many countries it is strictly forbidden to
  monitor spectrum occupancy or to publish
  monitoring data.

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National developments

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

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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