[en] The statistical characteristics of ionospheric irregularities are often described by specifying one or two of the statistical parameters of the scintillations that the irregularities produce in satellite radio signals. The most commonly used parameter for this purpose is the spectral index (slope of the power spectral density function on a log-log plot). While it is becoming increasingly clear that the characterization of either phase or amplitude scintillations by a single parameter may obscure significant characteristics of the scintillation, this simple approach has proven to be useful for the prediction of the behaviour of transionospheric propagation paths such as those used in various space application systems. This paper explores the use, in addition to the usual phase and amplitude observations, of measurements of angle-of-arrival, in order to characterize the scintillations. Since each of these observations represent a different kind of observational 'filtering', the combination of one statistical parameter from each type of measurement should provide a more adequate characterization of the scintillations. It is found that the use of the widths of the auto-correlation functions for this purpose is preferred over the use of spectral indices

[en] The results obtained from the differential phase measurements made during the Waterhole experiment are described. While there is evidence that the electron concentration in the immediate neighbourhood dropped as expected, the more dramatic outcome was the sudden cessation of particle precipitation. The radio measurements show that the electron concentration in the E-region below the 'hole' began to decay at the time of the explosion with a rate which is consistent with recombination. It continued to decay over the time that it could be observed, about 2.5 min. It must be concluded that the particle precipitation along magnetic field lines through the hole was cut off for at least that length of time

[en] The ionospheric electron content was measured at La Ronge, Sask., for a variety of auroral conditions during the Pulsating Aurora Campaign in February of 1980. The two-frequency differential phase technique was used with the NNSS satellite beacons. Comparisons of optical data and the radio results indicate that for quite strong pulsations the electron content is modulated by less than 2 percent. Even this small change is somewhat larger than the purely temporal variations to be expected on the basis of currently-accepted relaxation times in the ionosphere. If the observed fluctuations are interpreted as representing both temporal and spatial variations, good agreement is obtained with model calculations. For irregularity sizes and strengths to which the experiment is sensitive, structure was present in diffuse or patchy aurora but absent from at least some well-defined forms. This suggests that the technique can be used to explore the mechanism of formation of the irregularities. (auth)