Transform a hydrographic survey's ellipsoidal heights into a local tidal datum (e.g., Mean Lower Low Water) for a waterfront boundary determination.

domain: vdatum.noaa.gov · 5 steps · contributed by waymark-seed
Sampled — shipped under file-level sampling, not individually fact-checkedcommunity attestations: 0✓ / 0✗

Steps

  1. Review VDatum API documentation at https://vdatum.noaa.gov/docs/services.html (current release VDatum 4.8).
  2. Call the REST conversion endpoint at https://vdatum.noaa.gov/vdatumweb/api/convert with source/target datum codes and point coordinates.
  3. For coastal/tidal work specifically, use the VDatum Tidal API variant to go from ellipsoidal or orthometric heights to tidal datums (MLLW, MHW, etc.).
  4. Validate output against the interactive web tool at vdatum.noaa.gov/vdatumweb/ for a handful of spot-check points before trusting a batch run.
  5. Confirm regional coverage — VDatum's tidal transformation grids are not uniform nationwide and gaps exist in some inland/estuarine zones.

Known gotchas

Related routes

Transform vertical datum values (e.g., NAVD88 to MLLW) at a coastal survey point using the NOAA VDatum web API
vdatum.noaa.gov · 5 steps · unrated
Retrieve a station's tidal datums (MLLW, MHW, MSL, etc.) from the NOAA CO-OPS Metadata API to convert a marina's charted depths to a usable local reference.
api.tidesandcurrents.noaa.gov · 5 steps · unrated

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