HF Radio Communication Systems Design Assessment
Abstract
Ionospheric sounding may be divided into the two following general classes of operation: (a) true-path ionospheric sounding and (b) ionsopheric parameter probing. Ionospheric sounding is used for both HF communications and for basic research purposes. True-path ionospehric soundign is used solely for Hf communications, which contrasts with ionospheric parameter probing (or radar techniques) which providesa basis for ionospheric prediction besides supplementing basic research. HF communication sounding is, generally, a pre- link-establishment process for macroscopic frequency selection. True-path ionospheric soundign should be distinguished from communication channle evaluation (in-band evaluation) since in-band evaluation is a post-link- establishment process for determining the quality of a given circuit. Sounding equipment is usually separate from the communications equipment as is spectrum monitoring; however,j in-band channle evaluation hardware/software may be merged within the demodulation process as discussed. In the beginning, vertical incidence soundings were used to acquire data on which were based a frequency prediction sysem published in 1954 and which forms the basis of the current prediction system. Oblique soundigns were first used to test and improve the predictions and understanding of ionospheric propagation. Later, oblique sounding was proposed as a real-time aid to communications.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 30, 1980
- Accession Number
- ADB053107
Entities
People
- S. J. Smith