{ "culture": "en-US", "name": "MD_montgomery_dem_m", "guid": "", "catalogPath": "", "snippet": "Bare earth Digital Elevation Model (DEM) in feet elevation units. 2020 data collection. Geographic Extent: Montgomery County, Maryland. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification, Version 2.1. The data was developed based on a horizontal projection/datum of State Plane Maryland FIPS 1900, NAD83(2011), meters and vertical datum of NAVD88 (GEOID18). Class 2 (Ground) lidar points in conjunction with the hydro breaklines were used to create a 1 foot hydro-flattened Raster DEM", "description": "The lidar project called for the Planning, Acquisition, processing and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.35 meters. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification, Version 2.1. The data was developed based on a horizontal projection/datum of NAD83 (HARN), State Plane, Feet and vertical datum of NAVD88 (GEOID12B), Feet. Lidar data was delivered as processed Classified LAS 1.4 files, formatted to 1374 individual 6000 ft x 4000 ft tiles, as tiled intensity rasters, and as tiled bare-earth DEMs; all tiled to the same 6000 ft x 4000 ft schema. Ground Conditions: Lidar was collected in late 2020 to early 2021, while no snow was on the ground and rivers were at or below normal levels. In order to post process the lidar data to meet task order specifications and meet ASPRS vertical accuracy guidelines, Sanborn Map Company, Inc., utilized a total of 10 ground control points that were used to calibrate the lidar to known ground locations established throughout the project area. An additional 120 independent accuracy check points, 120 in Bare Earth and Urban landcovers (120 NVA points), were used to assess the vertical accuracy of the data. These check points were not used to calibrate or post process the data.", "summary": "Bare earth Digital Elevation Model (DEM) in feet elevation units. 2020 data collection. Geographic Extent: Montgomery County, Maryland. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification, Version 2.1. The data was developed based on a horizontal projection/datum of State Plane Maryland FIPS 1900, NAD83(2011), meters and vertical datum of NAVD88 (GEOID18). Class 2 (Ground) lidar points in conjunction with the hydro breaklines were used to create a 1 foot hydro-flattened Raster DEM", "title": "MD_montgomery_dem_m", "tags": [ "MD iMAP", " MD", " Maryland", " Montgomery", " LiDAR", " DEM" ], "type": "Image Service", "typeKeywords": [ "Data", "Service", "Image Service", "ArcGIS Server" ], "thumbnail": "", "url": "https://lidar.geodata.md.gov/imap/rest/services", "minScale": 1.8489297737236E7, "maxScale": 18055.954822, "spatialReference": "WGS_1984_Web_Mercator_Auxiliary_Sphere", "accessInformation": "", "licenseInfo": "Users should be aware that temporal changes may have occurred since this dataset was collected and that some parts of these data may no longer represent actual surface conditions. Users should not use these data for critical applications without a full awareness of its limitations. Any conclusions drawn from the analysis of this information are not the responsibility of the U.S. Geological Survey or its partners. Acknowledgement of the U.S. Geological Survey would be appreciated for products derived from these data. The Spatial Data, and the information therein, (collectively the \"Data\") is provided \"as is\" without warranty of any kind, either expressed, implied, or statutory. The user assumes the entire risk as to quality and performance of the Data. No guarantee of accuracy is granted, nor is any responsibility for reliance thereon assumed. In no event shall the State of Maryland be liable for direct, indirect, incidental, consequential or special damages of any kind. The State of Maryland does not accept liability for any damages or misrepresentation caused by inaccuracies in the Data or as a result to changes to the Data, nor is there responsibility assumed to maintain the Data in any manner or form. The Data can be freely distributed as long as the metadata entry is not modified or deleted. Any data derived from the Data must acknowledge the State of Maryland in the metadata." }