Accession Number : AD0011255


Title :   COMPARISON OF POWER SPECTRUM ESTIMATES OF OVERWATER MICROWAVE RADIO SIGNAL AND ASSOCIATE WATER WAVES


Corporate Author : TEXAS UNIV AT AUSTIN ELECTRICAL ENGINEERING RESEARCH LAB


Personal Author(s) : McKune, William J ; Smith, H W


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/011255.pdf


Report Date : 06 May 1953


Pagination or Media Count : 37


Abstract : Preliminary investigations of power spectrum estimates for sign al strength and corresponding sea-state time fluctuations are reported for an overwater path between 2 drilling platforms off Grand Island, Louisiana. The transmitters were located on the seaward drilling platform at heights of either 15 or 38 ft mean sea level. The receivers were on the shoreward platform at heights of either 14 or 53 ft mean sea level. The platforms were 5027 ft apart and 8 mi off shore. Measurements were made with the antenna both horizontally and vertically polarized. A record of wave heights was taken with a step-type wave gage, with steps every 0.2 ft. Curves, plotted on a normalized basis, show the power spectra of the signal strength and simultaneous sea state, and the relative power for the sea-state variations. The signal strength in decibels was plotted on normal distribution coordinates. It was concluded that the correspondence between the power spectra for signal strength and sea state is better for the longer wave lengths, the power spectra for the 0.86-cm signal strength show little similarity to the sea state and contains higher frequencies than are present in the sea state, the rms value of the signal-strength fluctuations is larger for the shorter wave lengths, and the signal-strength distribution is approximately log-normal, but the sea-state data show some deviation from either a normal or a log-normal distribution. The method of obtaining the power spectrum estimates is given.


Descriptors :   *RADIANT INTENSITY , *SEA STATES , *RADIO SIGNALS , VARIATIONS , STRENGTH(GENERAL) , MEXICO GULF , FREQUENCY RESPONSE , OFFSHORE , ESTIMATES , POWER SPECTRA , PATHS , SYNCHRONISM


Subject Categories : Radiofrequency Wave Propagation


Distribution Statement : APPROVED FOR PUBLIC RELEASE