National Elevation Dataset

The National Elevation Dataset (NED) consists of high precision ground surface elevation data for the United States. It was maintained by the USGS and all the data is in the public domain. Since the 3D Elevation Program came online, the NED was subsumed[1] into The National Map as one of its layers of information.

Sources

The NED dataset is a compilation of data from a variety of existing high-precision datasets such as LiDAR data (see also National LIDAR Dataset - USA), contour maps, USGS DEM collection, SRTM and other sources which were reorganized and combined into a seamless dataset, designed to cover all the United States territory in its continuity.

Formats

Data is available in a few popular formats such as ESRI ArcGRID, GeoTIFF, BIL, GridFloat, and a few others.

Precision

Depending on area location, the datasets are provided with 1/9 (about 3 meters), 1/3 (about 10 m) and 1-arcsecond (about 30 m) precision.

gollark: > As opposite extreme you could have a country with a super strict and specific constitution that is too holy for any politician to change (maybe a theocracy) but the gov controls most of the industryThe *government* still has a lot of political power inasmuch as it controls lots of things.
gollark: No planet, so... ageoism?
gollark: Conversely, if you control a lot of what people do you control a lot of the flow of money.
gollark: If you control a large amount of the flow of money in a country, you also control a lot of what people do.
gollark: They are VERY RELATED, though, and your unrealistic example doesn't change that.

References
  1. The National Map elevation information


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