Method for Remotely Detecting Tides and the Height of Other Surfaces
Patent, Filed 24 Jun 96, patented 30 Dec 97
DEPARTMENT OF THE NAVY WASHINGTON DC
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Transmitted signals are used to accurately and remotely determine the vertical distance of an earth-based receiving antenna above a surface. and hence can be used to determine the tide condition of a water surface. A signal is transmitted from a signal source as it moves either through air or space. An antenna whose height is to be determined with respect to a reflecting surface, such as water, receives the signal directly from the signal source and indirectly from the signal source by reflection of the signal from the reflecting surface. The sum of the directly and indirectly received signals form an interference pattern as the signal source is moved. Points on the interference pattern are selected at identical phase angle for each cycle of the pattern. The points are assigned reference numbers and the numbers are plotted with respect to a measurement indicative of the distance between the signal source and the antenna whose height with respect to the reflecting surface is to be determined. The slope or gradient of the reference numbers with respect to this measurement is determined. Reference interference patterns are generated either through mathematical modeling andor through direct physical measurement and these are used to establish an equation relating known antenna-to-surface distances to the slopes of the reference numbers verses measurement. The slope corresponding to the antenna of an unknown distance from a surface is inserted into this equation and the equation is solved for the unknown distance.
- Physical and Dynamic Oceanography
- Miscellaneous Detection and Detectors
- Radio Communications