A STATISTICAL STUDY OF UHF AURORAL BACKSCATTER AT LARGE MAGNETIC ASPECT ANGLE - A REANALYSIS OF UNPUBLISHED RESULTS FROM 1968

In 1968 a joint study of radal-auroral backscatter was carried out by Bell Laboratories, Western Electric, and Lincoln Laboratory using the 448-MHz radar of the Prince Albert Radar Laboratory. They made observa tions covering a range of magnetic aspect angles from 4.5 degrees to 1 6 degrees, but the results were not published in the open literature. These data have been reanalyzed and used to obtain results on the aspe ct sensitivity, flow angle dependence, absolute scattering cross secti on, Doppler velocity distributions, and the azimuthal variation of Dop pler velocity for large aspect angle auroral backscatter. The average aspect sensitivity was found to be independent of aspect angle and to decrease with increasing backscatter power. Estimates of the largest a bsolute scattering cross sections were much greater than previous esti mates at the same aspect angles, but these cross sections appear to be consistent with previous values once the long duration of the experim ent is taken into account. Backscatter power was found to be essential ly independent of flow angle.