{ "culture": "en-US", "name": "SacDelta_LiDAR_201712", "guid": "", "catalogPath": "", "snippet": "Orthomosaic of the Sacramento-San Joaquin Delta collected in 2017.", "description": "Product: This data set is comprised of classified LiDAR point cloud tiles in LAS 1.4 format, 0.5-meter bare-earth digital elevation models (DEMs) in ERDAS IMG format, 0.5-meter digital surface models (DSMs) in ERDAS IMG format, 0.5-meter intensity imagery tiles in GeoTIFF format, and hydro-flattened breaklines in Esri file geodatabase format.\n\nGeographic Extent: Approximately 1,312 square miles across several counties in central California.\n\nDataset description: The CA Sacramento Delta LiDAR 2017 D16 LiDAR project called for the planning, acquisition, processing, and production of derivative products of LiDAR data to be collected at a nominal pulse spacing (NPS) of 0.35 meters. Project specifications were based on the U.S. Geological Survey National Geospatial Program LiDAR Base Specification, Version 1.2. The data was developed based on a horizontal datum/projection of NAD83 (NSRS2007) UTM Zone 10 (EPSG 3717) meters, and a vertical datum of NAVD88 (GEOID12B), US survey feet. LiDAR data was delivered as processed classified LAS 1.4 files formatted to 1,706 individual 1,500-meter x 1,500-meter tiles. Other LiDAR products include tiled intensity imagery, tiled bare-earth DEMs, and tiled first return DSMs, all tiled to the same tiling schema.\n\nThis version of the data is referenced to the 2017 epoch, which is different from the USGS version that is referenced to the 2011 epoch.\n\nGround Conditions: LiDAR was collected from December 9, 2017 through January 21, 2018 by Woolpert, while no snow was on the ground and rivers were at or below normal levels. Saturated or partially flooded farm fields were identified following data acquisition. Through technical guidance discussions with USGS and the California Department of Water, it was determined such areas shall not be considered hydrologic features. Intermittently, partially flooded, irregular, and apparently non-agricultural fields were treated as hydrologic features. In all cases, best professional judgement was used in determination of treatment. In order to post process the LiDAR data to meet task order specifications and meet ASPRS vertical accuracy guidelines, Woolpert established 35 ground control points that were used to calibrate the lidar to known ground locations established throughout the project area. An additional 143 independent accuracy checkpoints (75 NVA points and 68 VVA points), were collected and used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data.\n\nThis data set was collected and produced by Woolpert for purposes of and under contract to USGS. Data are considered public domain.\n\n\n\nDWR makes no warranties or guarantees \u2014 either expressed or implied \u2014 as to the completeness, accuracy, or correctness of the data. DWR neither accepts nor assumes liability arising from or for any incorrect, incomplete, or misleading subject data. \n\nThis is an official DWR Image Service, published on June 13, 2019 by Stephanie Baker of the Division of Engineering, Geodetic Branch, Geospatial Data Support Section, who may be contacted at stephanie.baker@water.ca.gov, or 916-653-9815.", "summary": "Orthomosaic of the Sacramento-San Joaquin Delta collected in 2017.", "title": "SacDelta_LiDAR_201712", "tags": [ "orthophotography", "California", "Sacramento", "San Joaquin", "Delta" ], "type": "Image Service", "typeKeywords": [ "Data", "Service", "Image Service", "ArcGIS Server" ], "thumbnail": "thumbnail/thumbnail.png", "url": "https://parcgis.water.ca.gov/arcgisimgpublicmngr/admin/Aerial_Photography/SacDelta_LiDAR_201712/ImageServer", "spatialReference": "NAD_1983_NSRS2007_UTM_zone_10N", "accessInformation": "California Department of Water Resources, USGS, Woolpert", "licenseInfo": "None" }