STANFORD UNIVERSITY
EE 350 RADIOSCIENCE SEMINAR
Professor Umran Inan

Winter 2000-2001

Date: Wednesday, March 14, 2001
Time: 4:15-5:30 PM; Refreshments at 4:00 PM
Location:Bldg. 200, Rm. 34


MULTI-SPECTRAL FAR ULTRAVIOLET IMAGING OF THE AURORA

Dr. Steve Mende
Space Sciences Lab., UC Berkeley

Abstract

Direct imaging of the magnetosphere by instruments on the IMAGE spacecraft are supplemented by observation of the global aurora.  To assure the simultaneity of these observations and the measurement of the magnetospheric background neutral gas density three Far Ultraviolet (FUV) instruments are included on IMAGE.  The wavelength region 120-170 nm is most suitable for a downward-viewing auroral imager because it is only minimally contaminated by scattered sun light and radiance of the aurora can be observed even in the presence of the high-latitude dayglow.  The Wide-Band Imaging Camera (WIC) provides broad band ultraviolet images of the aurora for maximum spatial and temporal resolution by imaging the LBH N2 bands of the aurora.  The Spectrographic Imager (SI), a dual wavelength channel monochromatic imager, images the Doppler-shifted Lyman alpha, the proton-induced aurora component in one channel and auroral 135.6 nm OI in the other.  Images show that all instruments are capable of making very sensitive measurements with high spatial resolution even in the presence of summer sunlit conditions.  It was also demonstrated that the SI12 channel is capable to "see" the energetic protons through the detection of Doppler shifted Lyman alpha.  It was also shown that the WIC observes the aurora primarily in emissions of N2 and N while the SI13 channel is mainly sensitive to oxygen emission at O 135.6 nm.  The behavior of the aurora during a substorm is described using the IMAGE data.