The Particle Environment Monitor (PEM) on NASA's Upper Atmosphere
Research Satellite (UARS) measures the type, amount, energy, and
distribution of charged particles injected into the Earth's
thermosphere, mesosphere, and stratosphere. PEM consists of four
instruments: the ... Atmospheric X-Ray Imaging Spectrometer (AXIS),
the High Energy Particle Spectrometer (HEPS), the Medium Energy
Spectrometer (MEPS), and the Vector Magnetometer (VMAG).
The UARS PEM level 2 VMAG DC daily product (UARPE2VMAGDC) contains
the Vector Magnetic Field component, UARS
Aspect Magnetometers component, and UARS Torquer Bars component data
converted to nanoTesla and milliAmp units.
The VMAG DC range is -65000 nT to +65000 nT with 2 nT resolution. Its
measurement is from three vector components, X, Y, and Z. The VMAG sensor
consists of three orthogonal ring-core fluxgate sensors, surrounded by a
thermal sphere. Stray magnetic fields from the spacecraft can be accounted
for by use of the UARS torquer bar currents.
The VMAG unit is located on a stub boom mounted to the zenith particle
package. The zenith particle package is mounted on the zenith boom of
UARS. The UARS aspect magnetometers and torquer bars are located on the
body of the UARS spacecraft.
There is one data file per day for the PEM VMAG DC product, and the
temporal coverage is from Oct. 1, 1991 to Aug. 23, 2005. Spatial
coverage for the VMAG DC product ranges between -57 and +57 deg latitude.
The VMAG DC data files are written in network binary format. For more
information please review the PEM VMAG DC data format guide.