BackForwardInstrument:  RPI 

Instrument details
Acronym RPI
Full name Radio Plasma Imaging
Purpose To characterize plasma in the Earth's magnetosphere utilizing imaging in the radio frequency range.
Short description Low-power radar which operates in the radio frequency bands which contain the plasma resonance frequencies characteristic of the Earth's magnetosphere (3 kHz to 3 MHz). The instrument consists of an electronics enclosure, four 250 m wire antennae with deployers (including switches and couplers), and a z-axis boom canister containing two 10 m lattice boom antennae and two preamplifiers. The measured plasma density varies from 5 particles/cm3 at the magnetopause to 100000 particles/cm3 in the ionosphere
Background New development
Scanning Technique Volumetric exploration of the magnetosphere as the satellite moves along the Highly Eliptical Orbit
Resolution N/A
Coverage / Cycle Full magnetospheric volume
Mass 49.8 kg Power 30.8 W Data Rate


Providing Agency NASA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 2000 to 2005-12-15
Last update: 2017-04-23
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
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
Electric Field4 - fairNo specific limitation.Earth's limb. Electric field
Ionospheric plasma density*4 - fairNo specific limitation.Earth's limb. Ionospheric plasma density
Ionospheric Radio Absorption1 - primaryNo specific limitation.Earth's limb. Active radio waves
Electron Density*4 - fairNo specific limitation.Platform. Electron density
Ionospheric Vertical Total Electron Content (VTEC)1 - primaryNo specific limitation.Earth's limb. Active radio waves
Ionospheric Scintillation1 - primaryNo specific limitation.Earth's limb. Scintillations. Active radio waves