Tropical Propagation Research

The over-all objective of this program is to collect and analyze radio propagation data from actual representative environments needed to advance the state-of-the-art in the design and development of improved radio communication systems in these environments. The report summarizes the results of a series of specialized measurements, using pulse and swept-frequency transmitted signals. Various types of amplitude, frequency, and phase displays were recorded at the test receiver locations. The objective of these measurements was to obtain data which exhibit the multipath characteristics of the jungle path. The report discusses the methods of making these measurements, and the results of a limited analysis of the data. The probability distributions of signal amplitude at VHF in the tropical rain forest test area in Thailand are presented. These distributions are generally a prerequisite to the practical estimation of error rate performance of digital, or wideband, systems in this type of environment. An example is given in which the experimental probability distributions are used to obtain the error rate in an FSK modulation system in this type of environment. See also Volume 2 (Final), AD706232.