General Information:

• Places
• Structures
• Transportation
• Boundaries
• Hydrography
• Orthoimagery
• Land Cover
• Elevation

Along with providing access to the data, the site contains:

• Tutorial to help with downloads
• Information about the downloadable products
• Frequently Asked Questions
• Links to product homepages and information pages

The National Map Seamless Server is always growing with new data, tools, features, and much more.

The National Map Seamless Server capabilities include:

• Free downloads up to 3 Gbytes of data in 250 MB files in one request.
Users have unlimited access to the interactive map and can make unlimited requests. The amount of coverage area depends on the number of products selected for download. For example, if NED 1 Arc Second is selected as the only product a user can download up to a 30 square degree area. But, if NED 1 arc second and NED 1/3 arc second are selected, then the area available for download will be considerably smaller. To see the various sizes of coverage area for each product, click on the List of Products drop down, select the desired product.
• User can define an area of interest by drawing a box, defining coordinates, or use available templates to cut out the area.
The first method of drawing a box (square or rectangle) is best for defining a general area. The coordinates are displayed, in decimal degrees, in the bottom left corner of the window as the mouse is moved over the map. The second method of defining coordinates can be used when the user wants a precise area and knows the corner coordinates. The third method is the use of provided templates, such as 7.5 min quadrangles.
• NEW Feature (8-07-2007) -- Tiled Data Distribution System (TDDS)
The Tiled Data Distribution System (TDDS) allows a user to access historical data from the EROS storage system. The concept of The National Map Seamless Server is to provide the best available data. In the case of the high resolution orthoimagery, the best available will change approximately every couple of years. The older imagery will be removed from The National Map Seamless Server and map services and made available using TDDS.
• Query tools are provided to acquire more information about the an area of interest.
An example of the two query tools are Elevation Point and Elevation Profile. The elevation point tool allows a user to click anywhere on the map interface and an elevation will be returned, in feet, as well as the coordinates. The elevation profile tool will provide a cross section graph between two points, in any direction.

The goal is to provide as much information as possible. Please contact us with any suggestions or comments concerning The National Map Seamless Server and data.