BackForwardInstrument:  TPMU 

Instrument details
Acronym TPMU
Full name Thermal Plasma Measurement Unit
Purpose To study the ionosphere, its dynamics and response to solar and geomagnetic activity by measuring electron temperature, floating potential, and ion temperature, concentration and composition
Short description Ion measurements exploit a Retarding Potential Analyzer (RPA) technique. Electron temperature measurement is based on the radio frequency probe technique using a RF signal. Dynamic range of plasma density: 20-80000 particles/cm3
Background Part of a package of instruments for observation of solar activity and ionospheric effects
Scanning Technique In-situ measurement in a dawn-dusk orbit
Resolution N/A
Coverage / Cycle N/A
Mass 2.4 kg Power 1 W Data Rate


Providing Agency ESA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 2009 to 2024
Last update: 2021-12-10
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
  • Subcomponent 2
  • Magnetospheric energetic particles and magnetometers
  • Ionospheric total electron content sensor [at LEO and cross magnetosphere]
  • Ionospheric plasma density
  • Radio wave receiver [in LEO and cross magnetosphere]
Mission objectives
Primary mission objectives
  • Ionospheric plasma density
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
Note: * Primary mission objective.
VariableRelevance for measuring this variableOperational limitationsExplanation
Ionospheric plasma density*4 - fairNo specific limitation.Platform. Ionospheric plasma density
Ionospheric Radio Absorption4 - fairNo specific limitation.Interplanetary. Active radio waves
Ionospheric Total Electron Content (TEC)5 - marginalNo specific limitation.Platform. Active radio waves