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.
- Availability: This Government-owned invention available for U.S. licensing and, possibly, for foreign licensing. Copy of application available NTIS.
Department of the NavyConstitution Avenue and 18th Street, NW
Washington, DC USA
- Melling, N D
- DeMatteo, J J
- Levrant, M A
- Juels, R J
- Publication Date: 1977-3-30
- Pagination: 13 p.
- TRT Terms: Accelerometers; Contours; Gravity; Hydrographic surveying; Laplace transforms; Mapping; Patent applications; Patents; Ship motion; Surveying
- Uncontrolled Terms: Heaving
- Old TRIS Terms: Cascade structures; Heave response; Hydrographic surveys; Patents (Heave meters)
- Subject Areas: Hydraulics and Hydrology; Marine Transportation; Vehicles and Equipment;
- Accession Number: 00166614
- Record Type: Publication
- Source Agency: National Technical Information Service
- Report/Paper Numbers: PAT-APPL-782 661 Patent
- Files: TRIS
- Created Date: Oct 29 1978 12:00AM