VDatum

"The National Oceanic and Atmospheric Administration (NOAA -//www.noaa.gov/) has developed a revolutionary vertical datum transformation tool (VDatum) to address the inconsistent datum problem. A datum is the reference level to which geospatial data are gathered. For example, in the interest of navigational safety, NOAA collects water depth data to Mean Lower Low Water, and shoreline data to Mean High Water. The U.S. Geological Survey presently has their land elevation data referenced to Mean Sea Level and other datums. Geospatial data collected by NOAA and many other agencies and entities, particularly data collected in coastal regions, suffer from being tied to many different vertical reference datums.

VDatum translates geospatial data between 36 different vertical reference systems and removes the most serious impediments to data sharing allowing for the easy transformation of elevation data from one vertical datum to another. Geospatial data can be seamlessly integrated for the benefit of the U.S. public for applications such as Homeland Security and natural disaster preparedness. VDatum also allows NOAA to make full use of recent technological advancements [such as integration of depth data from an aircraft using a laser (LIDAR)] that will greatly improve the efficiency with which it acquires new and more accurate data for NOAA’s nautical, navigational, and geospatial products and services. VDatum will also improve the efficiency and accuracy of hydrographic surveys for nautical charts by eliminating the need for time-consuming water level corrections and post processing.

 The features include:

• Coordinate Systems:  Geographic, UTM, State Plane Coordinates (SPC), and geocentric (ECEF)
• Horizontal Datums:  NAD27, NAD83(1986), and NAD83(HARN); and ellipsoidal datums such as of ITRF, WGS84, and NAD83 serializations
• Vertical Datums: 
  
  • Ellipsoidal Datums: NAD83, WGS84, ITRF88, ITRF89, ITRF90, NEOS 90, PNEOS 90, ITRF91, ITRF92, SIO/MIT 92, ITRF93, ITRF94, ITRF96, ITRF97, IGS97, ITRF2000, IGS00, IGb00, ITRF2005, IGS05, ITRF2008, IGS08, WGS84(transit), WGS84(G730), WGS84(G873), WGS84(G1150), WGS84(G1674), NAD83(PACP00), NAD83(MARP00)
  • Orthometric Datums:   NAVD88, NGVD29, PRVD02, VIVD09, ASVD02, GUVD04, NMVD03, HAWAII EGM2008, EGM1996, and EGM1984
  • Tidal Datums: MLLW, MLW, LMSL, DTL, MTL, MHW, LWD, and MHHW
    
  • IGLD85
• GEOID models: GEOID12B, GEOID12A, GEOID09, GEOID06 (Alaska only), GEOID03, GEOID99, and GEOID96
• EGM models: EGM2008, EGM1996, and EGM1984
• Supported file format: text(ASCII), LiDAR(.LAS) version 1.0 to 1.2, ESRI ASCII Raster(.ASC), and ESRI 3D shapefile
  
  
  https://vdatum.noaa.gov/
  
  https://pubs.usgs.gov/ds/0848/html/ds848_data-processing.html