Vertical reference datums determination for hydrographic applications in Cartagena Bay

Abstract

The Oceanographic and Hydrographic Research Center CIOH on behalf of the Maritime Authority DIMAR, commit­ted to the process of regulation and standardization of the activities that take place in the jurisdiction of the Cartagena's port, especially bathymetric surveys carried out in the Bay, defined Datum or reference hydrographic vertical levels based on a methodology that combines the use of 2011 recorded water level data in the mareographic station located at the pier of CIOH in the Bay of Cartagena, mathematical calculations with the records obtained and field work results to establish the relationship between national geodetic network and vertical levels obtained, so that in this way generate the metadata that allows refer hydrographic survey to the levels determined according to the needs and purpose work. The Datum obtained were: MLWS (Mean Low Water Springs) used for referencing Colombian official nautical charting, LAT (Lowest Astronomical Tide) and MSL (mean sea level), all previous datums are recommended by the IHO (International Hydrographic Organization) for vertical referencingin hydrographic surveys especially MLWS and LAT. Also were calculated the MHWS (Mean High Water Springs) and HAT (Highest Astronomical Tide) datums. Adittionaly to the cartographic generation purposes, the results obtained will allow expand the range of products, analysis and derived studies from calculation, implementation and standardization of vertical levels such as of fusions with spatial data product of land surveying, use of the methodology for measuring rise and fall of water level through RTKGNSS technology being this one the highest accuracy available today in the development of hydrographic surveys, by the maritime authority have the support technical for require the standardization to same vertical reference level of hydrographic surveys development by external entitles, generating a efficient control that finally will resolve discrepancies that have occurred constantly when confronted products of different entities.