BackForwardInstrument:  EFW (CLUSTER) 

Instrument details
Full name Electric Fields and Waves
Purpose To measure electric field and density fluctuations, determine electron density and temperature, study nonlinear processes that result in acceleration of the plasma
Short description Double probe mounted on two pairs of wire booms, each 100 m tip-to-tip. Range 0.1-700 mV/m (electric field) and 0.01-100 kHz (waves)
Background Part of a package of instruments for the study of the Magnetosphere
Scanning Technique Formation flight of 4 satellites in coordinated high-elliptical orbits cross the Magnetosphere for 3-D field reconstruction
Resolution N/A
Coverage / Cycle Full magnetospheric volume; sampling at 0.1 ms intervals
Mass Power Data Rate


Providing Agency ESA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 2000 to ≥2020
Last update: 2017-04-13
Detailed characteristics
Satellites this instrument is flying on

Note: a red tag indicates satellites no longer operational, a green tag indicates operational satellites, a blue tag indicates future satellites

Instrument classification
  • Solar and space environment monitors
  • Field or radiowave sensor
Mission objectives
Primary mission objectives
  • Electric Field
Secondary mission objectives
  • Electron Density
  • Ionospheric plasma density
Opportunity objectives
  • Geomagnetic field
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Tentative Evaluation of Measurements

The following list indicates which measurements can typically be retrieved from this category of instrument. To see a full Gap Analysis by Variable, click on the respective variable.

Note: table can be sorted by clicking on the column headers
VariableRelevance for measuring this variableOperational limitationsExplanation
Geomagnetic field5 - marginalNo specific limitation.Magnetic field measured through observation of oscillations of the electric fileld
Electric Field1 - primaryNo specific limitation.Cluster in the magnetosphere. Electric field, wide dynamic range
Ionospheric plasma density3 - highNo specific limitation.Ionospheric plasma density measured through observation of oscillations of the electric field
Electron Density3 - highNo specific limitation.Electron density measured through observation of oscillations of the electric field