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    <title>Transport Research International Documentation (TRID)</title>
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
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    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
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      <title>HEAVE METER</title>
      <link>https://trid.trb.org/View/56580</link>
      <description><![CDATA[The patent describes a contour mapping system including compensation for the heave or vertical displacement of a ship due to wave and swell effects, and for correcting errors due to such effects in depth or bottom contour measurements of a body of water. Vertical acceleration A(s) of the ship, measured by a gravity meter accelerometer, is filtered according to the following LaPlace transform equation by a cascaded series of filters to yield ship vertical displacement. This series of filters accomplishes attenuation of noise, such as is caused by gravity, vertical coriolis, vertical vibration or electrical noise, in the acceleration signal, and double integration of the remaining acceleration signal. The displacement signal is then provided to the processor or system being used for depth measurement or contour mapping, so that the individual measurements made therewith are corrected for ship heave occurring during those measurements.]]></description>
      <pubDate>Sun, 29 Oct 1978 00:00:00 GMT</pubDate>
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