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elevation/swp_2016_lidar (ImageServer)

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Service Description: 1 meter Digital Elevation Model created from 2016 LIDAR survey of the State Water Project performed by Towill, Inc., for California DWR. Units are in feet, referenced to NAVD88. DWR makes no warranties or guarantees — either expressed or implied — 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. This is an official DWR Image Service, published on 9/13/2017 by Joel Dudas of the Division of Engineering, Geodetic Branch, Geospatial Data Support Section, who may be contacted at Joel.Dudas@water.ca.gov, or 916-651-7002. Survey Control – Ground control survey for this project was provided by Towill, Inc. The primary project control points were established using static GPS methods in compliance with Federal Geodetic Control Committee (FGCC) guidelines for First Order GPS surveys. The primary control network was used as a framework for surveying DWR’s existing survey monuments, establishing aerial targets, and tying in the CGPS reference stations supporting the airborne data collection efforts. Details of the survey control are contained in the PDF document entitled “14750-0107 Final Survey Control Report 20161216” prepared by Lisa M. Henstridge, PLS and dated December 20, 2016. Airborne Data Acquisition - The LiDAR survey was accomplished using an Optech Orion M300 LiDAR system operating from a rotary wing aircraft (Bell 206L3 Long Ranger). The airborne mission was conducted July 29 - August 3 and August 26-27, 2016. The airborne mission plan was based on the following parameters: Aircraft Flight Altitude: 750m Aircraft Speed: 60 knots Number of Flight lines: (followed aqueduct centerline) Nominal Point Density: 9 PPM^2 Custom Project Projection – Towill developed for this project “SWP2016” custom map projection based on the Hotine Oblique Mercator Azimuth Center system. All LiDAR data were processed and classified using SWP2016 and then reprojected to their respective California Coordinate System (CCS) Zones 2,3,4,5, and 6. LAS files were delivered in both CCS and the SWP2016 systems. LiDAR Data Post-Acquisition Processing - Using Novatel, Inc.’s 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’s POSPac software, version 4.3. Optech’s LiDAR Mapping Suite (LMS) – The 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’s 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 “bare-earth” surface were used to generate three separate deliverables: ArcGIS DEM – all ground points are used with ArcGIS 10.3 to develop a 32-bit raster DEM with a 1ft GSD. InRoads Terrain Surface – “bare-earth” ground is keypointed and MicroStation is used to create an InRoads TIN surface. Civil 3D Surfaces - “bare-earth” ground is keypointed and AutoCAD is used to create an Civil 3D TIN surface. LAS Point RGB Assignments - The aerial imagery was used to assign RGB values to the classified LAS files using MARS software developed by Merrick & Company. Credits

Name: elevation/swp_2016_lidar

Description: 1 meter Digital Elevation Model created from 2016 LIDAR survey of the State Water Project performed by Towill, Inc., for California DWR. Units are in feet, referenced to NAVD88. DWR makes no warranties or guarantees — either expressed or implied — 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. This is an official DWR Image Service, published on 9/13/2017 by Joel Dudas of the Division of Engineering, Geodetic Branch, Geospatial Data Support Section, who may be contacted at Joel.Dudas@water.ca.gov, or 916-651-7002. Survey Control – Ground control survey for this project was provided by Towill, Inc. The primary project control points were established using static GPS methods in compliance with Federal Geodetic Control Committee (FGCC) guidelines for First Order GPS surveys. The primary control network was used as a framework for surveying DWR’s existing survey monuments, establishing aerial targets, and tying in the CGPS reference stations supporting the airborne data collection efforts. Details of the survey control are contained in the PDF document entitled “14750-0107 Final Survey Control Report 20161216” prepared by Lisa M. Henstridge, PLS and dated December 20, 2016. Airborne Data Acquisition - The LiDAR survey was accomplished using an Optech Orion M300 LiDAR system operating from a rotary wing aircraft (Bell 206L3 Long Ranger). The airborne mission was conducted July 29 - August 3 and August 26-27, 2016. The airborne mission plan was based on the following parameters: Aircraft Flight Altitude: 750m Aircraft Speed: 60 knots Number of Flight lines: (followed aqueduct centerline) Nominal Point Density: 9 PPM^2 Custom Project Projection – Towill developed for this project “SWP2016” custom map projection based on the Hotine Oblique Mercator Azimuth Center system. All LiDAR data were processed and classified using SWP2016 and then reprojected to their respective California Coordinate System (CCS) Zones 2,3,4,5, and 6. LAS files were delivered in both CCS and the SWP2016 systems. LiDAR Data Post-Acquisition Processing - Using Novatel, Inc.’s 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’s POSPac software, version 4.3. Optech’s LiDAR Mapping Suite (LMS) – The 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’s 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 “bare-earth” surface were used to generate three separate deliverables: ArcGIS DEM – all ground points are used with ArcGIS 10.3 to develop a 32-bit raster DEM with a 1ft GSD. InRoads Terrain Surface – “bare-earth” ground is keypointed and MicroStation is used to create an InRoads TIN surface. Civil 3D Surfaces - “bare-earth” ground is keypointed and AutoCAD is used to create an Civil 3D TIN surface. LAS Point RGB Assignments - The aerial imagery was used to assign RGB values to the classified LAS files using MARS software developed by Merrick & Company. Credits

Single Fused Map Cache: false

Extent: Initial Extent: Full Extent: Pixel Size X: 1.0

Pixel Size Y: 1.0

Band Count: 1

Pixel Type: F32

RasterFunction Infos: {"rasterFunctionInfos": [{ "name": "None", "description": "", "help": "" }]}

Mensuration Capabilities: None

Inspection Capabilities:

Has Histograms: true

Has Colormap: false

Has Multi Dimensions : false

Rendering Rule:

Min Scale: 0

Max Scale: 0

Resampling: false

Copyright Text: NA

Service Data Type: esriImageServiceDataTypeGeneric

Min Values: -19.950000762939453

Max Values: 5392.33056640625

Mean Values: 1070.9916436962026

Standard Deviation Values: 1123.987701052008

Object ID Field: OBJECTID

Fields: Default Mosaic Method: Northwest

Allowed Mosaic Methods: NorthWest,Center,LockRaster,ByAttribute,Nadir,Viewpoint,Seamline,None

SortField:

SortValue: null

Mosaic Operator: First

Default Compression Quality: 75

Default Resampling Method: Bilinear

Max Record Count: 1000

Max Image Height: 4100

Max Image Width: 15000

Max Download Image Count: 20

Max Mosaic Image Count: 20

Allow Raster Function: true

Allow Copy: true

Allow Analysis: true

Allow Compute TiePoints: false

Supports Statistics: true

Supports Advanced Queries: true

Use StandardizedQueries: true

Raster Type Infos: Has Raster Attribute Table: false

Edit Fields Info: null

Ownership Based AccessControl For Rasters: null

Child Resources:   Info   Histograms   Statistics   Key Properties   Legend   Raster Function Infos

Supported Operations:   Export Image   Query   Identify   Compute Histograms   Compute Statistics Histograms   Get Samples   Compute Class Statistics   Query GPS Info   Find Images   Image to Map   Map to Image   Measure from Image   Image to Map Multiray   Query Boundary   Compute Pixel Location   Compute Angles   Validate   Project