TROPICAL PROPAGATION RESEARCH
Semiannual rept. no. 8, 1 Jul-31 Dec 1966
ATLANTIC RESEARCH CORP ALEXANDRIA VA JANSKY AND BAILEY ENGINEERING DEPT
Pagination or Media Count:
This is a report on a research program involving studies of the propagation of radio waves in a tropically vegetated environment. It represents the first report of activities in an area located about 40 miles from the coastal town of Songkhla in southern Thailand. A primary objective of this work is to supplement and also provide a comparison with the results, described in previous reports, of the extensive experimental and theoretical program near Pak Chong, Thailand. Songkhla is classified as a rainy tropical region and is characterized as having a 50 per cent heavier rainfall and much denser and taller vegetation than Pak Chong, which is classified as a wet-dry tropical region. Contained in the report are descriptions of the environment in the test area and of the test facilities that have been established. The experimental goals and test procedures are set forth, covering such topics as the effects upon transmission loss of frequency, antenna heights, polarization, and transmission range. Some preliminary results of measurements, based on all the data obtained from Songkhla as of 31 December 1966, are given in the form of 15 plots of basic transmission loss as a function of distance for various frequencies, transmitting antenna heights, and paths. The receiving antennas are fixed at a height of 6 feet, and the polarization is horizontal. Much of the instrumentation used at Songkhla is the same as that used at Pak Chong. Several changes, however, were necessary and are described in the report.
- Radio Communications