NOPR Collection:

Mid-latitude D-Region Electron Density Profiles at Different Solar Activities Adapted to LF, MF & HF Propagation Data

Fri, 01 Mar 1974 00:00:00 GMT

Title: Mid-latitude D-Region Electron Density Profiles at Different Solar Activities Adapted to LF, MF & HF Propagation Data Authors: Singer, W.; Bremer, J. Abstract: Mean D-region electron density profiles are derived for medium latitudes and summer conditions at low solar activity (R < 30) for the solar zenith angles 40°,60°,70°,80^o, as well as at high solar activity (R = 110) for the solar zenith angle 80°. In the derivation of these profiles, data from rocket measurements, partial reflection measurements, absorption measurements in the LF, MF and HF band, phase height measurements in the LF band, and critical frequencies of the E-Iayer have been used. The profiles do not show a distinct CR-D-layer and allow a fairly good interpretation of the radio propagation data and their dependence on solar zenith angle. The profiles are in good agreement with rocket profiles of K. Maeda [J. Geomagn. Geoelect. Japan, 21 (1969), 557] and of Mechtly et al. [J. atmos. terr. Phys., 34 (1972), 1899]. Page(s): 119-124

Use of LF & VLF Propagation Data in Studies of Electron Density Profiles at Mid-latitudes

Fri, 01 Mar 1974 00:00:00 GMT

Title: Use of LF & VLF Propagation Data in Studies of Electron Density Profiles at Mid-latitudes Authors: Bain, W. C. Abstract: The VLF and LF propagation parameters are calculated from all available electron density distributions for' mid-latitudes under sunspot-maximum conditions at times near noon. The results are compared with average observed values In England, and a dose agreement was not obtained with any one of the measured distributions. An indication is given of how model ionospheres, suitable for propagation calculations, might be derived for winter and equinox conditions. Page(s): 113-118

D-Region Electron Density Profiles in Mid-latitude Stations

Fri, 01 Mar 1974 00:00:00 GMT

Title: D-Region Electron Density Profiles in Mid-latitude Stations Authors: Hirao, K. Abstract: The available data on ionospheric D-region and the methods used for such study are discussed. No categorical dependence, either geographical or geomagnetic, is noticed for the D-region. The pattern of diurnal variation has also been only partially explained so far. It Is suggested that improved rocket probe should be designed in order to get reliable synoptic data about the D-region ionosphere. Page(s): 109-112

Electron Density Profiles Deduced from Absorption Measurements

Fri, 01 Mar 1974 00:00:00 GMT

Title: Electron Density Profiles Deduced from Absorption Measurements Authors: Rangaswamy, S. Abstract: A numerical technique for obtaining model electron density profiles of the D• and lower E-regions from ground-based absorption measurements, is described. The technique is used to deduce model electron density profiles using limited data obtained at an equatorial station. The resultant profiles are found to be in good agreement with those obtained concurrently with the absorption measurements at a nearby location with rocket experiments. Page(s): 104-108