NRCS/USDA Geospatial Data Gateway
http://datagateway.nrcs.usda.gov/GatewayHome.html


Program Highlights
Data Product
* The Geospatial Data Gateway provides One Stop Shopping for natural resources or environmental data
* Source for USDA Countywide Compressed Orthophoto Mosaics

Advantages
* Data downloads are free and near-real time
* Compressed, mosaiced counties are easier to work with, color/tone balanced, and potentially more accurate than individual quarter quad NDOP DOQs

Disadvantages
* Compression of imagery may degrade visual quality
* County mosaics generally use first generation NDOP imagery so they are fairly old.
* USDA is not the authoritative source for all data on the site, so some data may be out of date

Program Overview
The Geospatial Data Gateway is intended to provide a single access point for resource data.  It provides a way to easily locate data that exist for selected geographic areas, find the types of data for that area, and deliver the data packaged in formats compatible with commercial and USDA Service Center application formats.

One major purpose of the Gateway is to support the development, presentation, and dissemination of information by Service Center field staff working in the field with customers away from the office. However, the public has access to the Gateway to find and retrieve resource data.

Data Details
The data sets served by the Gateway are primarily determined by the USDA Service Center Geographic Information System (GIS) Strategy. The data themes are listed on the Gateway Data Management page (http://datagateway.nrcs.usda.gov/data.html).  This page also identifies non-geospatial data that may be available through the Gateway.

By using the FGDC metadata standards, the Geospatial Data Gateway can serve data to Federal Clearinghouse nodes and become a node itself for those layers for which the USDA is the steward.

Data Applicability to Flood Mapping Program
County orthophoto mosaics can be used as FEMA base maps provided the compression does not reduce the usability of the image.  These mosaics are much easier to work with, have more consistent image brightness, contrast and sometimes improved positional accuracy compared to the first generation tiled DOQs.

Data Availability
The Geospatial Data Gateway provides access to many different data layers, which may be updated as frequently as once per week.  The most critical themes are generally available nationwide.

Critical Themes
* Orthoimagery
* Soils
* Common Land Unit (CLU)

Data Ordering
Data is available for order online at http://datagateway.nrcs.usda.gov/NextPage.aspx.  Users can download the data from the website directly, retrieve it from an FTP site, or order it on CD or DVD.