We are currently experiencing intermittent issues impacting performance. We apologize for the inconvenience.
By Topic

Sporadic E at VHF in the USA

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

3 Author(s)
Davis, R.M. ; Central Radio Propagation Lab., Nat''l. Bur. Standards, Boulder, Colo. ; Smith, E.K. ; Ellyett, C.D.

An analysis is made of sporadic-E propagation observed on the Cedar Rapids to Sterling path during the four years, 1952-1955. VHF transmissions over this path at frequencies of 27.775 mc and 49.8 mc provided the Es data. At this latitude, the summer months receive the preponderance of sporadic E. Diurnally, sporadic-E occurrence tends to favor the day-time and evening hours with peaks of incidence about 1000 and 1800. No variation with sunspot number has been discerned. As a rule, higher Es signal intensities are recorded at 28 than at 50 mc. Cumulative distributions of signal intensity are presented for the two frequencies. A relationship is found between the frequency dependence of Es signal intensities ¿ -70 db, relative to inverse distance, and the distribution of fEs values at Washington, D.C. The relationship promises to be useful in the prediction of Es signal intensities on a worldwide basis. An inverse correspondence is shown between sporadic-E occurrence and geomagnetic activity. The correspondence holds only over selected time intervals. The frequency dependence of received power under sporadic-E conditions is different from that during normal scatter. The median frequency exponent is two or more times as large for sporadic E, and the exponents cover a much wider range of values. This is tentatively explained by considering the Es region to be composed of patches of intense nonuniform ionization, an hypothesis previously used to explain vertical-incidence data.

Published in:

Proceedings of the IRE  (Volume:47 ,  Issue: 5 )