2014 USACE NCMP Topobathy Lidar: California

These files were collected by Fugro and contain topographic data collected with a RIEGL VQ-480 airborne lidar system over the California coastline. Data coverage generally extends along the shoreline from the waterline to 500 meters onshore. The VQ-480 sensor configuration produced a pulse repetition rate of 200 kHz at near-infrared laser wavelength. VQ-480 data was collected concurrently with SHOALS-1000 bathymetric lidar sensor; the line scheme flown was planned for the narrower scan swath of the SHOALS sensor (230 m) therefore VQ-480 data presents overlap that exceeded over 200% (460 m) of area coverage and point density requirements. Quality assessments allowed to keep best quality flight line data and discard redundant or flight lines of lesser quality. Native lidar data are not generally in a format accessible to most Geographical Information Systems (GIS). Specialized in-house and commercial software packages are used to process the native lidar data into 3-dimensional positions that can be exported to standard formats and imported into GIS software for visualization and further analysis. Each flight line lidar data containing the XYZ points were exported to ASPRS LAS format. The data file naming convention is based on a standardized structure. LAS format is version 1.2. The files also contain airborne bathymetric lidar data collected with the SHOALS-1000T sensor over the California coast. Data coverage generally extends along the coastline from the waterline to 1,000 meters offshore or to laser depth extinction. The SHOALS system has a laser pulse repetition rate of 2.5 kHz at 532 nm (green wavelength). SHOALS lidar data are contained in two basic file types: HOF and INH. HOF files (Hydrographic Output File) contains the XYZ and supporting information for all shots within a flight line; the INH files (Hydrographic Input File) contains information describing the flight line and the digitized laser shot data (waveforms). These data formats, proprietary of Optech, Inc. (Canada), are commonly used in software packages that include SHOALS-GCS and CZMIL-HydroFusion. The Las files were then classified with class 1 being unclassified, 2 being ground and 29 valid bathymetric data in Terrascan. The 3-D position data are used to generate a series of LAS file products, with each covering approximately 5 kilometers of shoreline. In addition to the lidar point data, topobathy bare earth Digital Elevation Models (DEMs), created from the lidar point data are also available. These products have not been reviewed by the NOAA Office for Coastal Management (OCM) and any conclusions drawn from the analysis of this information are not the responsibility of NOAA or OCM. These data are available for download here: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=5189 DEMs that were created from all classes of points (1, 2, 29) at a 1 meter grid size are available by request via email at: coastal.info@noaa.gov.

Original contact information:

Contact Org: JALBTCX

Title: Data Production Manager

Phone: 228-252-1131

Email: JALBTCX@usace.army.mil

These data were collected as a part of the NCMP to depict the elevations above and below water in the California coastal zone. Data gaps that resulted from terrain, airspace restrictions (around LAX) and temporal changes in the beach profile.

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These data have been developed from the best available sources. Although efforts have been made to ensure that the data are accurate and reliable, errors and variable conditions originating from physical sources used to develop the data may be reflected in the data supplied. Users must be aware of these conditions and bear responsibility for the appropriate use of the information with respect to possible errors, scale, resolution, rectification, positional accuracy, development methodology, time period, environmental and climatic conditions and other circumstances specific to these data. The user is responsible for understanding the accuracy limitations of the data provided herein. The burden for determining fitness for use lies entirely with the user. The user should refer to the accompanying metadata notes for a description of the data and data development procedures. Any conclusions drawn from the analysis of this information are not the responsibility of JALBTCX, the Office for Coastal Management or its partners.

This data can be obtained on-line at the following URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=4912;

None. These data have been developed from the best available sources. Although efforts have been made to ensure that the data are accurate and reliable, errors and variable conditions originating from physical sources used to develop the data may be reflected in the data supplied. Users must be aware of these conditions and bear responsibility for the appropriate use of the information with respect to possible errors, scale, resolution, rectification, positional accuracy, development methodology, time period, environmental and climatic conditions and other circumstances specific to these data. The user is responsible for understanding the accuracy limitations of the data provided herein. The burden for determining fitness for use lies entirely with the user. The user should refer to the accompanying metadata notes for a description of the data and data development procedures.

These data depict the heights at the time of the survey and are only accurate for that time. Acknowledgement of the Joint Airborne Lidar Bathymetry Technical Center of eXpertise (JALBTCX) would be appreciated in any publications or derived products. The data herein, including but not limited to geographic data, tabular data, analytical data, electronic data structures or files, are provided "as is" without warranty of any kind, either expressed or implied, or statutory, including, but not limited to, the implied warranties or merchantability and fitness for a particular purpose. The entire risk as to the quality and performance of the data is assumed by the user. No guarantee of accuracy is granted, nor is any responsibility for reliance thereon assumed. In no event shall the U.S. Army Corps of Engineers, Mobile District Office, Spatial Data Branch be liable for direct, indirect, incidental, consequential or special damages of any kind, including, but not limited to, loss of anticipated profits or benefits arising out of use of or reliance on the data. The Spatial Data Branch does not accept liability for any damages or misrepresentation caused by inaccuracies in the data or as a result of changes to the data caused by system transfers or other transformations or conversions, nor is there responsibility assumed to maintain the data in any manner or form. Users should be aware that temporal changes may have occurred since this data set was collected and some parts of this data may no longer represent actual surface conditions. Users should not use this data for critical applications without a full awareness of its limitations.

Microsoft Windows 7 Version 6.1 (Build 7601) Service Pack 1; Esri ArcGIS 10.1.0.3035

These data are not attributed. | Quantitative Value: None | Quantitative Test Explanation: These data are not attributed.

Compiled to meet 1 m horizontal RMSE at 95% confidence level.

The Topographic data point positions were obtained using post processed KGPS methods. The vertical accuracy of the data is better than +/- 0.095 m. The Bathymetric data point positions were obtained using post processed KGPS methods. The vertical accuracy of the data is better than +/- 0.185 m

This data set covers the spatial extent of topographic and bathymetric lidar data obtained during this survey.

During inspection and QC of the lidar point cloud, flightline to flightline elevation differences met the RIEGL VQ-480 AND SHOALS-1000T sensor specifications.