There are significant uncertainties in the calculation of photometric and ionization masses of meteors, particularly those derived from meteor head echoes observed by high power, large aperture radars. Simultaneous observations of meteors with the EISCAT UHF tristatic system and narrow field two-station intensified video were conducted in October 2007; 11 hours of data produced four useful meteors observed on all three radar receivers and both cameras. The positions and speeds calculated on the two systems generally agree to within the observational uncertainty. The photometric and ionization masses for each meteor were calculated using several values of luminous efficiency and ionization probability from literature, and all of these masses were found to agree to within the estimated error in the methods. More observations are required to select among the various values of ionization coefficient and luminous efficiency. / <p>Ytterligare finansiär NASA för den kanadensiska delen</p> / meteor

It has been shown in previous studies that at 110 km altitude, the electron temperature can be quite large in the presence of strong electric fields. This thesis explores the possibility of deviations from the normal trends in the high latitude E-region electron heating in reaction to strong electric fields. The study is based on data from the EISCAT Incoherent Scatter Radar during the International Polar Year. Out of a large number of possibilities (the radar operated essentially on a continuous basis for a year) only seven events proved to have sufficiently strong electric fields and large enough plasma densities to be characterized as ‘good heating events’. The electron temperature enhancements in these events, at 110 km, were several hundred K above from the background temperature and correlated well with ion temperature at 150 km altitude. The results for these good events agreed very well with past studies, aside from the smaller starting temperatures which were likely connected to the quiet solar conditions at the time. This stated, a different type of E region electron heating event was identified. In that case the E region electron densities were small (night-time conditions free of electron precipitation) and the electron temperatures reached a maximum near 150 km altitude. In those events the electron temperature enhancements extended down to the lower altitudes, introducing small, but detectable, electron temperature enhancements all the way down to 105 km altitude. .