VDatum and Strategies for National Coverage

VDatum is a software tool being developed by the National Ocean Service that allows users to vertically transform geospatial data among a variety of ellipsoidal, orthometric and tidal datums. This is important to coastal applications that rely on vertical accuracy in bathymetric, topographic, and coastline data sets. The VDatum software can be applied to a single point location or to a batch data file. Applying VDatum to an entire data set can be particularly useful when merging multiple data sources together, where they must first all be referenced to a common vertical datum. Contemporary technologies, such as lidar and kinematic GPS data collection, can also benefit from VDatum in providing new approaches for efficiently processing shoreline and bathymetric data with accurate vertical referencing. VDatum is currently available for Tampa Bay, New York Bight, Delaware Bay, Louisiana's Calcasieu River and Lake Charles, central California, Puget Sound, Strait of Juan de Fuca, and north/central North Carolina. In addition, VDatum development is near completion for Chesapeake Bay, Mobile Bay to Cape San Bias, Southern California, Long Island Sound and New York Harbor, and projects are also commencing for an area from New Orleans to Mobile Bay, the Gulf of Maine and the Pacific Northwest. Given the numerous applications that can benefit from having a vertical datum transformation tool, the goal is to develop a seamless nationwide VDatum utility that would facilitate more effective sharing of vertical data and also complement a vision of linking such data through national elevation and shoreline databases.