Sporadic E propagation

Characteristics of Ionospheric Es Propagation and Calculation of Es Signal Strength

“…The strength has its maximum value at a distance of about 1,500 km because, while r decreases with d, the height gain of the antenna decreases with d above l ,500 km under the conditions given. This example gives a good explanation of the results of investigation of Es propagation in the United States, as reported byGerson (1955].…”

Oblique‐incidence sporadic‐E propagation and its ionospheric attenuation

“…In such records of complex signals, however, it should be noticed that the distance dependence of signal level is liable to be flattened so as to show a high level at a shorter distance. Figure 16 shows a frequency distribution with distance of 50 MHz radio contacts of 12,500 instances [ Gerson, 1955], that of 3,228 TV-DX reports [Smith, 1957], and the above estimated probabilities on 50 and 70 MHz signals under appropriate parameters. They agree, approximately, with each other, but the sporadi½-E events appear skewed toward shorter distances than estimated, which might, at least in part, be due to the geographical boundaries of the tests.…”

“…the US Gerson [1955]. andSmith [1957] collected reports of sporadi½-E events from 1949 through 1952 and from 1950 to 1953 in the US, and derived frequency distributions of the events with distance.…”