{
 "culture": "en-US",
 "name": "Bouldin_Island_DEM_20171130",
 "guid": "",
 "catalogPath": "",
 "snippet": "Digital Elevation Model of Boudin Island from November 30, 2017. ",
 "description": "The purpose of this project was to produce 1\"-40' topographic mapping and orthophoto imagery of Bouldin Island. The orthophotography encompassed the entire island and topographic mapping was produced for an area approximately 1850 acres near the center of the island. This work was performed under MWD Task Order 164106-1-104740. Survey Control Ground control survey for this project was established by Towill, Inc. based on RS 39-36 supplied by Metropolitan. Details of the control survey are available in the report file named \u201c15133-101_Bouldin_Island_Flight_Panel_Report_v1\u201d. In addition, Towill\u2019s field survey crews collected additional ground truth points in widely dispersed locations which were used to verify the vertical accuracy of the LiDAR dataset. LiDAR Acquisition The LiDAR survey was accomplished using an Optech Orion M300 LiDAR system operating from a fixed wing aircraft (Partenavia C-68 Tail #N6602L). \n\nThe mission was performed on November 30, 2017. The mission plan was based on the following: Aircraft Flight Altitude: 750m FT AGL Aircraft Speed: 120 knots Number of Flight lines: 20 Flight Line Spacing: 380m Nominal Point Density: 9 Points Per Square Meter (PPM^2)\n\nLiDAR Data Post-Acquisition Processing\nAirborne GPS Data Processing - Using Novatel, Inc.\u2019s Grafnav version 8.20 software, the differential kinematic data was processed from two base stations, and the solutions compared. This procedure is intended to verify the integrity of the base station coordinates and elevations. Each processing session was computed in both the forward and reverse temporal directions. The comparison of these solutions is intended to provide insight into the quality of the kinematic ambiguity resolution. The horizontal and vertical datums of the LiDAR data set were realized by adjusting the coordinates of the base station points and the relative application of the geoid model to the final data set. IMU Data Processing and Best Estimated Trajectory - The post-processed ABGPS trajectory was combined with the raw, high-frequency IMU observations in a loosely-coupled Kalman filter-based processing algorithm to produce the final high-frequency Smoothed Best Estimated Trajectory (SBET) using Applanix\u2019s POSPac software, version 4.3. Optech\u2019s LiDAR Mapping Suite (LMS) \u2013The ABGPS and integrated IMU data files were used as inputs to process the laser range files collected during the mission. The LMS software package assembles each of these three components and outputs fully georeferenced LAS strip files. The overlap between adjacent strip files are analyzed and if elevation differences exist, these values are used as feedback and the process is repeated. LiDAR Data Classification Terrasolid\u2019s Terrascan V.1.2 software was used to tile the LAS strip files into manageable size files and to run macro routines which assist in the ground classification. Bridges and other structures were manually reclassified as non-ground classes. Following a thorough QA/QC review by an analyst, ground points comprising the \u201cbare-earth\u201d surface were used to generate separate deliverables. Aerial Imagery Aerial imagery was acquired for the study area simultaneously with the LiDAR using a PhaseOne 4-Band 100 megapixel camera. The imagery was aerotriangulated using INPHO\u2019s MATCH-AT software and used to generate 4-band orthophoto imagery with a 0.25ft pixel resolution. The imagery was delivered as GeoTIF tiles and MrSID mosaics. Photogrammetric Mapping Planimetric features were stereo-digitized from the imagery using DATEM software and incorporated into the MicroStation DGN file. The mapping scale is 1\u201d-40\u2019 and has a one-foot contour interval. \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, 2018 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": "Digital Elevation Model of Boudin Island from November 30, 2017. ",
 "title": "Bouldin_Island_DEM_20171130",
 "tags": [
  "Airborne LiDAR",
  "Digital Elevation Model",
  "California Delta",
  "San Joaquin County",
  "Bouldin Island"
 ],
 "type": "Image Service",
 "typeKeywords": [
  "Data",
  "Service",
  "Image Service",
  "ArcGIS Server"
 ],
 "thumbnail": "thumbnail/thumbnail.png",
 "url": "https://parcgis.water.ca.gov/arcgisimgpublicmngr/admin/elevation/Bouldin_Island_DEM_20171130/ImageServer",
 "spatialReference": "NAD_1983_StatePlane_California_III_FIPS_0403_Feet",
 "accessInformation": "DWR Division of Engineering Geodetic Branch",
 "licenseInfo": "None"
}