Influence of vertical movement in bathymetries and its influence on the measurement conditions

Abstract

Bathymetries constitute a fundamental element of building objects settled on land submerged land: dikes, docks, underwater pipelines; in addition to dredges, volume of reservoir, etc. In civil engineering the bathymetry affect areas of small extent in which measures should be the most accurate as possible, influencing many factors in its precision. Among these factors can be distinguished: speed of sound in water, positioning system, vessel movements (pitch and roll) and vertical movement of the boat. Vertical movement of the vessel is perhaps one of the least studied factors, but their influence on the accuracy of bathymetries could be very important depending on swell conditions and depth that exists at the time of measurement. This paper defines a mathematical model based on measurements of bathymetry observed with GPS that lets you define wave conditions that found the boat according to its trajectory and speed. From this point, the article quantifies the effect of the vertical movement of the boat to correct its effect on the measured depths with an echo-sounder. Finally, from the results it is possible to obtain a set of recommendations about operations to measure a bathymetry depending on the accuracy that you should obtain.