UARS PEM Level 2 AXIS 1 V001 (UARPE2AXIS1) at GES DISC

The UARS Particle Environment Monitor (PEM) level 2 Atmosphere X-Ray Imaging Spectrometer (AXIS) unit 1 daily product contains the X-ray high-resolution spectral data converted to number intensity units from the AXIS1 pixels mounted on the UARS body. PEM was flown on the UARS spacecraft to measure the type, amount, energy, and distribution of charged particles injected into the Earth's thermosphere, mesosphere, and stratosphere.

The PEM AXIS1 X-ray data cover roughly the energy range from 2 keV to 300 keV. There are eight AXIS1 pixels mounted in the AXIS1 housing, each viewing different directions. The AXIS1 pixels are aligned on the spacecraft to project about 45 degrees toward the +x-axis direction from the Earthward pointing direction (+z-axis). Each pixel of AXIS1 is staggered about the 45 degree direction in an every-other fashion. Pixel 1 is closest to the center line of the spacecraft and Pixel 8 is furtherest away; however, their ground projection is dependent on the spacecraft orientation.

There is one data file per day for the PEM AXIS1 product, and the temporal coverage is from Oct. 1, 1991 to Aug. 23, 2005. Spatial coverage for the AXIS1 product ranges between -80 and +80 degrees latitude. The AXIS1 data files are written in network binary format. For more information please review the PEM AXIS1 data format guide.