The Mission


Spacecraft Instrumentation

The five spin-stabilized (spin period = 3 seconds) THEMIS probes carry the comprehensive packages of plasma and field instruments needed to determine the cause of geomagnetic substorms. The instruments being flown are:

Electric field instruments (EFI)
Fluxgate magnetometers (FGM)
Search coil magnetometers (SCM)
Electrostatic analyzers (ESA)
Solid state telescopes (SST)
Mechanical Drawings

Ground Based Instrumentation

The dedicated array of THEMIS ground observatories (20 all-sky imagers and 21 ground magnetometers) covers North America from Eastern Canada to Alaska, providing the information needed to place THEMIS probe observations within their global context. The ground observatories were up and fully operational prior to the launch of the THEMIS probes in February, 2007.

All-sky white light imagers (ASI)
Fluxgate magnetometers (GMAGS)

Other Fields Data

Digital Fields Board (DFB)-Filter Bank (FBK)-Fourier Power Spectra (FFT)
On-board Spin Fits (FIT) from EFI and FGM Instruments

Instrument Configuration History

Filter Bank (FBK) Signal Source Selections
Fourier Power Spectra (FFP, FFW, FFF) Signal Sources, Frequency Bin Counts, Cadence

Particle Instrument Configuration History (angle and energy bin counts, cadence):

ESA electrons
ESA ions
SST electrons
SST ions