VDatum is a free software tool developed jointly by NOAA's National Geodetic Survey (NGS), Office of Coast Survey (OCS), and Center for Operational Oceanographic Products and Services (CO-OPS). VDatum is designed to vertically transform geospatial data among a variety of tidal, orthometric and ellipsoidal vertical datums - allowing users to convert their data from different horizontal/vertical references into a common system and enabling the fusion of diverse geospatial data in desired reference levels.
VDatum was firstly introduced to produce a seamless bathymetric - topographic digital elevation model (DEM) for Florida's Tampa Bay region by merging the "best available" NOAA bathymetric data and USGS topography data. The best available bathymetric data were selected from the NOAA / NOS Hydrographic Survey database. For the Tampa bay region, approximately half of the sounding data were collected in reference to a mean low water (MLW) vertical datum, and the other half were collected for surveys using a mean lower low water (MLLW) vertical datum. The best available topographic data were selected from the USGS National Elevation Dataset (NED). NED dataset is horizontally referenced to NAD 83 and vertically referenced to NAVD 88. Prior to merging, both dataset were transformed to a common reference coordinate system, both horizontally and vertically, using VDatum.
The bathy-topo DEM has proved not only to solve the problem of inconsistency between diverse dataset of bathymetry, topography and shorelines data that has caused difficulty for mapping coastal regions, but also provides standard geospatial data for multiple applications. Applications benefiting from VDatum include:
Last Updated: Friday, December 19, 2008