DeLorme is pleased to announce the availability of NGS (National Geodetic Survey) benchmark data for XMap. These OpenSpace files, organized by state, can be downloaded for free and are compatible with all versions of XMap 5 or newer.
A benchmark is a geographic point whose coordinates and/or elevation has been measured and recorded to a high level of accuracy. Benchmarks are used by surveyors, engineers, map makers, and other professionals who need a highly accurate positional reference for their work. Recently, locating benchmarks has also become a popular pastime for the geocaching community.
Each benchmark or geodetic control station has a precise latitude/longitude used for horizontal control or a precise orthometric height used for vertical control or both a horizontal and vertical control.
The XMap data is comprised of individual OpenSpace layers created for all 50 U.S. states and the District of Columbia, based on data downloaded from the NGS benchmark archive files. Recent benchmark additions can be downloaded directly from the NGS website and appended to the appropriate XMap OpenSpace layer using the Import… Append function of XMap GIS Editor or XMap GIS Enterprise.
The benchmark layers have been classified and symbolized to distinguish horizontal and vertical benchmarks. Additionally, a unique symbol has been assigned to benchmarks that are considered both horizontal and vertical control points. Each layer includes four pre-defined queries that can be run from within the Attribute subtab of XMap: Search by County, Search by ID number, Search by Benchmark name, and Search by USGS Quad. The results of these queries are highlighted on the map and in the attribute table.
Each benchmark includes over 35 attribute fields, including its name, date established, and condition. Additionally, each point on the map is labeled with the benchmark ID number, which also serves as a hyperlink to the complete online datasheet for that control point.
As with all GIS layers in XMap, the benchmarks can be transferred to the PN-Series GPS receivers for field use. On the device, the objects that appear as labeled points on the screen are searchable using the Find function.
The availability of the benchmark data in XMap format is further evidence of DeLorme’s commitment to providing powerful geospatial tools and data in a cost-effective way, making GIS technology accessible to everyone.
