On the possibility of auroral remote sensing with the Viking ultraviolet imager

Journal Article · Sun Mar 01 04:00:00 EST 1992 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/91JA02608· OSTI ID:5595369

Steele, D P; McEwen, D J ^[1]; Murphree, J S ^[2]

---

1. Univ. of Saskatchewan, Saskatoon (Canada)
2. Univ. of Calgary, Alberta (Canada)

An investigation was carried out to assess the value of ultraviolet auroral images for remote sensing of electron precipitation. The authors compared auroral images, obtained by both cameras of the Viking Ultraviolet Imager during April and early May 1986, with simultaneous measurements of electron precipitation from the DMSP F7 and HiLat satellites at low altitudes above the auroral zone. The electron data were averaged over the image pixels and were used to normalize the imager signals to unit electron energy flux. The resulting quantity, here termed the effective sensitivity, showed large scatter about the mean values for both cameras that tended to mask any energy dependence except a decrease at electron energies above 6 keV. The mean effective sensitivities were 11.3 {plus minus} 1.1 digitization numbers (DN)/(erg cm{sup {minus}2}s{sup {minus}1}) for the Lyman-Birge-Hopfield (LBH) camera and 15.9 {plus minus} 2.5 DN/(erg cm{sup {minus}2}s{sup {minus}1}) for the 1304 camera. The signal ratio in simultaneous images from both cameras was insensitive to electron energy in the two cases examined, consistent with the weak energy dependences of the effective sensitivities. Unusually high LBH camera effective sensitivities of 45-60 DN/(erg cm{sup {minus}2}s{sup {minus}1}) were obtained during several orbits on May 2 and 3. They conclude that images from either Viking camera may be used to infer the instantaneous distribution of electron energy deposition, with roughly 50% accuracy.

• OSTI ID: 5595369
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 97:A3; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

661320* -- Auroral
Ionospheric
& Magnetospheric Phenomena-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AURORAL ZONES
CAMERAS
CHARGED-PARTICLE PRECIPITATION
CHEMICAL COMPOSITION
COMPARATIVE EVALUATIONS
EARTH ATMOSPHERE
ELECTRON PRECIPITATION
EVALUATION
IMAGES
MAGNETIC STORMS
REMOTE SENSING
SATELLITES
SENSITIVITY
THERMOSPHERE