About 1
What is 1? It's the new set of digital cartographic frameworks from The National Atlas of the United States of America® at a scale of 1:1,000,000. 1 also includes national elevation and land cover datasets at 100-meter ground resolution. How do I get 1? Go to nationalatlas.gov and follow the path for Mapping Professionals to get 1 via file transfer protocol or to use 1 as a Web Map Service (WMS). The WMS complies with the latest specification from the Open Geospatial Consortium. How much do you charge for 1? 1 is provided on-line at no cost to the end user. Why did you switch from two million- to one million-scale? 1 delivers more content and a greater level of detail. It allows us to harmonize authoritative small-scale base data from the United States with similar data from Canada and Mexico. 1 also delivers the United States contribution to the international Global Map effort. Is the two million-scale data still available? Yes, but 1 is replacing it. We don't plan to revise the two million-scale frameworks. What's this Global Map edition of 1? More than 100 national mapping organizations join together to produce consistent data of the world at one million-scale. 1 is the American contribution from the National Atlas to the international Global Map effort. The spatial data in all editions is the same, but data attributes in this edition conform to the latest Global Map data model and specification. |
What file formats can we expect? We plan to have a rolling release between now and the end of 2012. Initially, expect industry standard shapefiles. Next, we'll release ESRI geodatabases and GeoTIFFs. By the end of the year, we'll make 1 available in KMZ format and deliver prototype Web Feature and Web Coverage services, too. What do you mean by "networked hydrography?" America's surface waters are being delivered in two ways; as a set of national shapefiles and as 21 fully networked regional geodatabases that are built on the National Hydrography Dataset (NHD) model. Like the NHD, 1 contains a flow network that allows for tracing water downstream or upstream. It also uses an addressing system based on reach codes and linear referencing you can use to link specific information such as discharge rates and water quality. Each geodatabase includes streams, waterbodies & wetlands, coastlines, and gaging stations. Is 1 documented? Sure it's documented and you can't download 1 from us without getting full, extensive metadata, too. What's the map projection for 1? The vector files that you download will not be projected. These are delivered in geographic coordinates. Elevation and land cover datasets will be delivered in both Albers Equal Area and Lambert Azimuthal Equal Area map projections. Our WMS uses the EPSG:4326 projection and supports eleven others. What's the plan for 1 Web Feature Services? Coverage Services? Later this year, we will deliver Web Feature and Web Coverage services and poll our professional users to learn more about their expectations for these. |
