Data, Accuracy & Limitations | MapElevation

An estimate of the surface

MapElevation currently uses Copernicus GLO-30, a global digital surface model (DSM), delivered as terrain tiles by Mapterhorn. Every first-stage elevation query samples a zoom-12 tile. The original data resolution is approximately 30 metres: zooming further into the map does not improve the original data accuracy. Grade C identifies this global surface estimate; it is not a statement of a ±30 metre vertical error.

Buildings and tree canopies can raise a surface reading above the bare ground. A result is not the height of a specific floor, a surveyed benchmark, or a measure of current sea level. Negative elevations are possible. Values are rounded to whole metres or feet to avoid suggesting survey precision. The source vertical reference is the EGM2008 geoid; do not compare a result directly with a flood elevation in another datum.

Use and limitations

Results are estimates based on public datasets, not an official FEMA determination, land survey, flood warning or insurance recommendation. US flood tools query FEMA NFHL point features when available; a missing response does not establish that a property is outside a flood zone. A point does not represent the whole building footprint or parcel. BFE units and datums are preserved and are not subtracted from the global surface estimate.

The LOMA questionnaire identifies missing information and professional next steps. It does not determine eligibility, submit a request, or create a certificate. The sea-level demonstration is a bounded, static connected-water illustration with an assumed baseline in the DEM reference. It omits local tidal-datum conversion, infrastructure, waves, storm surge, erosion, subsidence, and drainage operations; it is not an address-specific forecast or a prediction for a particular year. Contours are derived from the surface model and are not a design survey. For decisions about property, construction or safety, consult the relevant official sources and a qualified local professional.

Data credits

produced using Copernicus WorldDEM-30 © DLR e.V. 2010-2014 and © Airbus Defence and Space GmbH 2014-2018 provided under COPERNICUS by the European Union and ESA; all rights reserved

Terrain tiles: © Mapterhorn. See the Mapterhorn data access documentation and the Copernicus licence.

Basemap: OpenFreeMap © OpenMapTiles, data from OpenStreetMap contributors.

US address locations: US Census Bureau Geocoder. Census locations may be interpolated along street address ranges. When global search is configured, address search also uses Geoapify. An address match does not guarantee a rooftop location.

Future regional data

The current version uses Grade C data worldwide. US 3DEP and Spain IGN upgrades are planned separately after this MVP. Japanese national data will remain disabled until its licensing requirements are confirmed. An upgrade will identify its actual source, resolution, model and vertical reference instead of inferring accuracy from map zoom.