Investigation of corona initiation voltage at reduced pressures

The results of an experimental study of the 60 Hz ac corona inception voltage at reduced pressures for a cylindrical conductor and a parallel ground plane are presented. Several spacings and bare and insulated conductors of several diameters are considered. Empirical expressions from which a reasonably accurate prediction of the corona inception voltage (CIV) may be made have been inferred from experimental data     

Application of the Spatial Spectral Power Density to the Calculation of Resolution Limits

Resolution as a function of aperture length in the presence of phase errors is investigated with the aid of the spatial power spectral density. Numerical calculations are made for power spectra thought to be appropriate for phase errors due to atmospheric turbulence. Both Gaussian and uniform illumination are considered, and the results obtained here are compared with those reported by Brown and Riordan [2].