A STATISTICAL DESCRIPTION OF AN IONOSPHERIC CHANNEL
Abstract
An experimental procedure to determine ionospheric-channel amplitude and phase statistics as a function of time and frequency is described. A coherent phase FM-CW sounder is programmed to sweep repetitively and rapidly (relative to ionospheric changes) a portion of the HF spectrum. The IF signal obtained by mixing the received signal with a replica of the transmitted signal possesses the amplitude and phase characteristics of the channel. These two characteristics are determined and subsequently analyzed by digital computer. Computer correlations were performed on signals received at Stanford, California, over a one-hop, lower-ray path from Lubbock, Texas, during 485 successive 16- to 16.5-MHz sweeps (one sweep each 0.5 s) of an FM-CW sounder. The test was performed under winter-noon conditions. The ionospheric amplitude vs frequency characteristics decorrelated to a value of 1/e in 3 s and 70 kHz. These values are probably set by received-signal polarization changes.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1967
- Accession Number
- AD0821960
Entities
People
- M. R. Epstein
Organizations
- Stanford University