Accession Number : AD0757343

Title :   A Prediction Scheme for the Lowest Observed Frequency (LOF) of the Guam-North West Cape HF Propagation Path and Eight Other Pacific Paths.

Descriptive Note : Research and development rept. Oct 70-Oct 72,

Corporate Author : NAVAL ELECTRONICS LAB CENTER SAN DIEGO CALIF

Personal Author(s) : Bleiweiss,Max P.

Report Date : 06 DEC 1972

Pagination or Media Count : 28

Abstract : A simple method for predicting the lowest observed frequency (LOF) of hf propagation paths - LOF proportional to (cos chi (sup 1/4), where chi is solar zenith angle - is presented. Predicted values of LOF in every case examined between midpath zenith angles of 5 and 85 are found to fall within the range of two standard deviations around the mean observed LOF. These findings - for the Guam to North West Cape (NWC), Australia, propagation path - are observed to match the results of a previous report on the Hawaii to California path. Predictions of the lowest useable frequency (LUF) provided by CNO are also compared with mean observed LOF values for the Guam-NWC path. Agreement is found to be good, though there are several exceptions. In addition, predictions are made for several other Pacific propagation paths. These are determined to fit the observed data well, with only one case of marked disagreement. It is concluded that the LOF prediction scheme is at least as good as the CNO LUF scheme, and less costly. (Author)

Descriptors :   (*RADIO TRANSMISSION, HIGH FREQUENCY), PACIFIC OCEAN ISLANDS, CALIFORNIA, CURVE FITTING, GRAPHICS, PERIODIC VARIATIONS, NOMOGRAPHS, SOLAR DISTURBANCES

Subject Categories : Radiofrequency Wave Propagation
      Radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE