BackForwardInstrument:  PWI 

Instrument details
Acronym PWI
Full name Plasma Waves Investigation
Purpose To study the wave phenomena related to plasma dynamics in the different regions on various scales (phenomena include magnetic-field-line merging, moving plasmoids, and particle acceleration)
Short description Plasma waves are measured in the frequency range 0.005-800 kHz. Electric fields are measured over the range 0.0005 -400 kHz, magnetic fields over the range 0.001-10 kHz.
Background Part of a package of instruments to observe the Magnetosphere by navigating across its tail
Scanning Technique Travelling cross the Magnetosphere in a highly-elliptical orbit
Resolution N/A
Coverage / Cycle Full magnetospheric volume
Mass Power Data Rate


Providing Agency JAXA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 1992-10-02 to ≥2021
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
WIGOS Subcomponents No WIGOS subcomponents have been defined.
Mission objectives
Primary mission objectives
  • Electron Density
  • Ionospheric plasma density
Secondary mission objectives
  • Electric Field
  • 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 Field2 - very highNo specific limitation.Electric field measured by magnetic and electric field oscillations
Ionospheric plasma density1 - primaryNo specific limitation.Ionospheric plasma density measured through observation of oscillations of the magnetic and electric fields
Electron Density2 - very highAssimilation in gravity model needed.. No specific limitation.Electron density measured through observation of oscillations of the magnetic and electric fields