Wideband HF Channel Prober: System Description.
Abstract
The high-frequency, extended-line-of-sight (HF ELOS) channel, which is planned as the primary intra-task-force communication link, is a multimodal channel involving modes of widely disparate characteristics. The surface-wave mode is relatively broadband, while the sky-wave modes are substantially more limited in bandwidth because of the inherently dispersive character of the ionospheric propagation medium. Environmental factors such as sea state, seawater temperature and salinity, atmospheric-refractive-index vertical profile, and ionospheric conditions all exercise strong influences over the link characteristics. A definitive data base from which to infer the broadband signaling characteristics of the channel is not presently available. The Wideband HF Channel Prober is a very short pulse (1-microsec) HF radio sounder with the necessary sensitivity, time resolution, and processing speed to monitor and record the details of the pulse response of the channel. To exploit fully the average-power capabilities of most high-power transmitters, a coded PM sequence is transmitted rather than a single pulse. The period of the PN sequence is designed to be comparable with the expected reverberation time of the channel. Correlation processing in the receiver results in a processing of gain of the order of 34 dB.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 09, 1983
- Accession Number
- ADA127040
Entities
People
- Eather A. Chapman
- Joseph A. Goldstein
- Leonard S. Wagner
Organizations
- United States Naval Research Laboratory