This is a 3 ft resolution digital elevation model derived from light detection and ranging (lidar). Lidar was collected in 2018 and coverage includes a portion of Clarksburg, Maryland, focused around the Clarksburg Special Protection Area (CSPA).

This is a 3 ft resolution digital elevation model derived from light detection and ranging (lidar). Lidar was collected in 2008 and coverage includes a portion of Clarksburg, Maryland, focused around the Clarksburg Special Protection Area (CSPA).

This is a 3 ft resolution digital elevation model derived from light detection and ranging (lidar). Lidar was collected in 2013 and coverage includes a portion of Clarksburg, Maryland, focused around the Clarksburg Special Protection Area (CSPA).

This dataset contains a 6 foot resolution digital elevation model (DEM) covering two watersheds in Clarksburg, Montgomery County, Maryland.

This dataset contains a digital elevation model (DEM) covering two watersheds in Clarksburg, Montgomery County, Maryland. This DEM has been hydrologically conditioned to breach detention basins, culverts, and other potential barriers to surface flow (i.e. ‘pits’).

This dataset contains digitized land use/land cover (LULC) polygons for years between 1998 and 2013 for six watersheds within and near the Clarksburg Special Protection Area located in Montgomery County, Maryland, USA. Each polygon is representative of the LULC for a specific year within 500-foot buffered watersheds. Watershed boundaries for Cabin Branch (CB), Crystal Rock (CR), Soper Branch (SB), Tributary 104 (T104), and Tributary 109 (T109) were derived using USGS topographic maps while Ten Mile Creek (TMC) was derived using Montgomery County, Maryland LiDAR data. The Habitat Digitizer Extension add-in from NOAA for ArcMap was used to customize a hierarchical classification scheme to attribute polygons delineated by visually interpreting aerial imagery and orthoimagery taken during tree leaf-off season.

A first surface elevation map (also known as a Digital Elevation Model, or DEM) of the Vicksburg National Military Park in Mississippi was produced from remotely sensed, geographically referenced elevation measurements cooperatively by the U.S. Geological Survey (USGS), National Park Service (NPS), and National Aeronautics and Space Administration (NASA). Elevation measurements were collected over the area using the NASA Experimental Advanced Airborne Research Lidar (EAARL), a pulsed-laser ranging system mounted onboard an aircraft to measure ground elevation, vegetation canopy, and coastal topography. The system uses high-frequency laser beams directed at the Earth's surface through an opening in the bottom of the aircraft's fuselage. The laser system records the time difference between emission of the laser beam and the reception of the reflected laser signal in the aircraft. The plane travels over the target area at approximately 50 meters per second at an elevation of approximately 300 meters. The EAARL, developed by NASA at Wallops Flight Facility in Virginia, measures ground elevation with a vertical resolution of 15 centimeters. A sampling rate of 3 kilohertz or higher results in an extremely dense spatial elevation dataset. Over 100 kilometers of coastline can be surveyed easily within a 3- to 4-hour mission. When subsequent elevation maps for an area are analyzed, they provide managers with a useful tool regarding land development. For more information on Lidar science and the Experimental Advanced Airborne Research Lidar (EAARL) system and surveys, see http://ngom.usgs.gov/dsp/overview/index.php and http://ngom.usgs.gov/dsp/tech/eaarl/index.php .