Data Management Plan

This publication presents lidar data collected over the community of Golovin, on the southern coast of the Seward Peninsula in western Alaska (fig. 1). The original data were collected on November 5, 2013, by Quantum Spatial. The complete, classified lidar dataset was purchased by the State of Alaska Division of Geological & Geophysical Surveys in 2014 in support of coastal vulnerability mapping efforts. For the purposes of open access to lidar datasets in coastal regions of Alaska, this collection is being released as a Raw Data File with an open end-user license. The horizontal datum for this dataset is NAD83 (CORS96), the vertical datum is NAVD88, Geoid 09, and it is projected in UTM Zone 3 North. Units are in Meters. Data have been classified to Ground (class 2) and Default (class 1). Quantum Spatial collected the Golovin LiDAR data on 11/05/2013.

Process Steps:

• 2013-11-05 00:00:00 - Acquisition. Quantum Spatial collected the Golovin lidar data on 11/05/2013. The survey used a Optech Gemini laser system mounted in a Piper Navajo. Data was collected using a single pulse flight plan. Ground level GPS and aircraft IMU were collected during the flight. Optech Gemini Instrument Parameters: Beam diameter: 26 cm, Pulse rate: 70 kHz, Maximum returns: 4, Field of view (FOV): 40 degrees, Beam wavelength: 1064 nm, Frequency of GPS sampling: 2 Hz, Frequency of IMU sampling: 200 Hz, AGL: 800 m, Average pulse density: 4
• 2014-09-16 00:00:00 - 1. Flight lines and data were reviewed to ensure complete coverage of the study area and positional accuracy of the laser points. 2. Laser point return coordinates were computed based on independent data from the lidar system, IMU, and aircraft. 3. The raw lidar file was assembled into flight lines per return with each point having an associated x, y, and z coordinate. 4. Visual inspection of swath to swath laser point consistencies within the study area were used to perform manual refinements of system alignment. 5. Custom algorithms were designed to evaluate points between adjacent flight lines. Automated system alignment was computed based upon randomly selected swath to swath accuracy measurements that consider elevation, slope, and intensities. Specifically, refinement in the combination of system pitch, roll and yaw offset parameters optimize internal consistency. 6. Noise (e.g., pits and birds) was filtered based on known elevation ranges and included the removal of any cycle slips. 7. Using TerraScan and Microstation, ground classifications utilized custom settings appropriate to the study area. 8. The corrected and filtered return points were compared to the RTK ground survey points collected to verify the vertical accuracy. 9. Data were classified to Ground (class 2) and Default (class 1).
• 2014-01-01 00:00:00 - File compression - LAS files were compressed to LAZ format to facilitate online distribution
• 2014-01-01 00:00:00 - Digital Surface Model (DSM) - The digital surface model (first returns) was generated from LAS files in ArcGIS using the LASD to Raster Tool.
• 2014-01-01 00:00:00 - Digital Terrain Model (DTM) - The digital terrain model (bare earth) was generated from LAS files in ArcGIS using the LASD to Raster Tool after filtering to only use ground points.
• 2014-01-01 00:00:00 - Hillshade images were derived from the digital terrain model and digital surface model with Global Mapper and exported as 3 Band GeoTIFFs.
• 2015-01-25 00:00:00 - The NOAA Office for Coastal Management (OCM) received the files in laz format from Alaska DGGS via an FTP online repository. The files contained lidar elevation and intensity measurements. The data were in UTM Zone 3, NAVD88 (orthometric) heights in meters. OCM performed the following processing for data storage and Digital Coast provisioning purposes: 1. The data were converted from UTM coordinates to geographic coordinates. 2. The data were converted from NAVD88 (orthometric) heights in meters to GRS80 (ellipsoid) heights in meters using Geoid 12a. 3. The LAS data were sorted by latitude and the headers were updated.

This data can be obtained on-line at the following URL:

https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=4799

The data set is dynamically generated based on user-specified parameters.;