Data and Documentation
The accepted framework layer for the elevation dataset in Montana is the USGS National Elevation Dataset.
National Elevation Dataset Information
The 3D Elevation Program (3DEP) initiative is being developed to respond to growing needs for high-quality topographic data and for a wide range of other three-dimensional representations of the Nation’s natural and constructed features. The primary goal of 3DEP is to systematically collect enhanced elevation data in the form of high-quality light detection and ranging (lidar) data over the conterminous United States, Hawaii, and the U.S. territories, with data acquired over an 8-year period. Interferometric synthetic aperture radar (ifsar) data will be collected over Alaska, where cloud cover and remote locations preclude the use of lidar over much of the State. The 3DEP initiative is based on the results of the National Enhanced Elevation Assessment.
The National Elevation Dataset (NED) is a new raster product assembled by the U.S. Geological Survey. NED is designed to provide National elevation data in a seamless form with a consistent datum, elevation unit, and projection. Data corrections were made in the NED assembly process to minimize artifacts, perform edge matching, and fill sliver areas of missing data.
Interagency Elevation Inventory
On-line inventory of known and accepted high resolution elevation data for the nation.
Elevation data refers to a representation of spatially referenced vertical positions above or below a datum surface. This type of geospatial data may be represented by elevation values separated by a consistent grid spacing in the form of the United States Geological Survey’s (USGS) Digital Elevation Models also known as DEMs, or may be derived from Light Detection and Ranging technology known as lidar or by Interferometric Synthetic Aperture Radar known as ifSAR. The NED is designed to provide National elevation data in a seamless form with a consistent datum, elevation unit, and projection. Data corrections were made in the NED assembly process to minimize artifacts, perform edge matching, and fill sliver areas of missing data. Both the one arc-second (approximately 30-meter) and one third arc-second (approximately 10 meter) data has been collected and processed for the state of Montana. The 3DEP program is being developed to respond to the states need for high-quality enhanced elevation data. The National Enhanced Elevation Assessment has identified over 602 mission-critical activities that require enhanced elevation data. For Montana these include: Flood Risk Management, Infrastructure Management, Geologic Resources and Hazards Mitigation, Precision Farming and Natural Resources Conservation.