Ion Density, Drift Velocity, and Temperature Measurements Made by Earth Observation Satellites

CEOS EO HANDBOOK – MEASUREMENT INSTRUMENTS

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Gravity, Magnetic and Geodynamic measurements >
Ion Density, Drift Velocity, and Temperature

Measurement Definition*: An instrument that measures the amount of ions encountered by the spacecraft, and attempts to deflect them to assess their velocity and temperature.

Instrument	Status/ Accuracy	Instrument Description	Measurement Technology	Timeline
IRM Imaging and Rapid-scanning ion Mass spectrometer	Operational	Measures the composition and 3-dimensional velocity distributions of ions.	n/a
IVM Ion Velocity Meter	Operational	Measures the in-situ plasma density, ion temperature and composition, and drift velocity. Used for modeling the ionosphere to determine electric fields that could impact other systems (e.g. GPS radio signals).	n/a
SEP Space Environment Monitoring Instrument Package	Operational	A suite that contains energetic particle detectors, magnetometer, and space weather impact detectors, among which, the energetic particle detectors measure high energy protons (0.4~4MeV) and high energy electrons (1~165MeV, and >165MeV) with two probes. Particle flux detection is performed in multiple directions with a number of probes mounted toward different orientation on the three-axis stabilized spacecraft. The space weather impact detectors measure radiation dosage, electrification at the surface and deep inside the spacecraft. It’s the first time China put space weather impact and space environment detectors on the same geostationary platform.	n/a
SSI/ES-3 Special Sensor Ionospheric Plasma Drift/Scintillation Meter	Operational	Measurement of the ambient electron density and temperatures, the ambient ion density, and ion temperature and molecular weight.	n/a

* Description adapted from WMO.