The Impact of NOAA’s Height Modernization Program

The New York Times (Jonathan Corum), based on NOAA and NGS data

Last month the New York Times covered a subject that you’d expect to be too technical for the general reader: NOAA’s efforts to recalibrate elevation data as part of its update to the National Spatial Reference System, expected in 2022 or 2023. The height modernization program corrects local elevation data—which was last updated in 1988—by using GPS and gravity mapping. The Times article looks at the real-world implications of this effort, which will have the greatest impact the further west and north you go (see map above), from bragging rights about mountain elevation to whether your community is in a floodplain. [MAPS-L]

Previously: NATRF2022 Datum Coming to North America in 2022.

NATRF2022 Datum Coming to North America in 2022

Geoff Zeiss posts about the forthcoming NATRF2022 datum, which will replace NAD 83 and NAVD 88 in 2022. It will address the shortcomings of the earlier datums and for the first time provide a common datum for Canada, the U.S. and Mexico. “Practically,” Geoff writes, “this means that elevations may change by up to a meter and horizontal location by up to 1.5 meters. The actual corrections to elevations and horizontal locations will depend on where you are in North America. The greatest changes are in the Pacific Northwest and the least in the southeastern U.S.” [Dave Smith]