Accession Number:

AD0801581

Title:

THE OPTIMUM RANGE FOR HF COMMUNICATION.

Descriptive Note:

Technical rept.,

Corporate Author:

STANFORD UNIV CA STANFORD ELECTRONICS LABS

Personal Author(s):

Report Date:

1966-09-01

Pagination or Media Count:

13.0

Abstract:

A study of HF communication indicates that for best signal-to-noise ratio there exists an optimum distance between transmitter and receiver, assuming a system which always operates on the frequency that maximizes the received signal-to-noise ratio. Computations were made assuming four different spherical ionospheres corresponding to summer and winter, noon and midnight, at a temperature latitude. A broadband vertically steerable antenna of fixed area was assumed at one end of the path and isotrope at the other. The calculations were performed with the aid of a digital computer, taking into account such effects as ray focusing and the variations of noise, absorption, and antenna gain with frequency. The results show that the signal-to-noise ratio increases with the range by amounts varying from 20 to 30 db, between roughly 500 and 3000 km. At longer ranges, the signal-to-noise ratio decreases due to the decrease in antenna gain for low angles.

Subject Categories:

  • Radio Communications

Distribution Statement:

APPROVED FOR PUBLIC RELEASE