Lidar data for the community of Golovin, Alaska

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.

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.

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A report for this project is available at:

https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid12b/4799/supplemental/ak2013_DGGS_golovin_m4799_surveyreport.pdf

A footprint of this data set may be viewed in Google Earth at:

https://noaa-nos-coastal-lidar-pds.s3.amazonaws.com/laz/geoid12b/4799/supplemental/ak2013_DGGS_golovin_m4799.kmz

LAS 1.2 format (classes 1,2)

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Any conclusions drawn from the analysis of this information are not the responsibility of Quantum Spatial, Alaska DGGS, NOAA, 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=4799

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

This report, map, and/or dataset is available directly from the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys

Any hard copies or published datasets utilizing these datasets shall clearly indicate their source. If the user has modified the data in any way, the user is obligated to describe the types of modifications the user has made. The user specifically agrees not to misrepresent these datasets, nor to imply that changes made by the user were approved by the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys. The State of Alaska makes no express or implied warranties (including warranties for merchantability and fitness) with respect to the character, functions, or capabilities of the electronic data or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products or any failure thereof or otherwise. In no event will the State of Alaska's liability to the Requestor or anyone else exceed the fee paid for the electronic service or product.

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. These data depict the heights at the time of the survey and are only accurate for that time.

Accuracy statements are based on areas of moderate terrain. Diminished accuracies are to be expected in areas of extreme terrain and dense vegetation. The accuracy of each point is expected to meet the vertical accuracy standard, however, derived products may be less accurate in extreme terrain and dense vegetation due to a lesser number of points defining the bare-earth in these areas. Questions regarding data accuracy can be best answered by Quantum Spatial (Anchorage, Alaska) staff.

The Optech Gemini system has a stated horizontal accuracy of 1/5500 x altitude. The Golovin lidar data was flown at 800m AGL resulting in a horizontal accuracy of 15 cm.; Quantitative Value: 0.15 meters, Test that produced the value: 15 cm

The Root Mean Square Error (RMSE) of the vertical accuracy of this dataset is 0.107 m. Accuracy was assessed using 15 ground survey points. Please see the lidar data report for a discussion of the statistics related to this dataset. The vertical accuracy of the lidar dataset was independently evaluated by DGGS using control points (n=10) that were collected by DGGS during the course of 2012 fieldwork. The standard deviation of the differences between these independent control points and the lidar point-cloud data confirmed the vertical accuracy reported by Quantum Spatial in the 2014 delivery report.; Quantitative Value: 0.107 meters, Test that produced the value: 10.7 cm RMSEz

LiDAR data has been collected and processed for all areas within the project study area. AKDGGS's area of interest (AOI) was larger in extent than the previous AOI for which the data was acquired. This resulted in small but unavoidable data gaps along the northern boundary and lower point densities in the eastern section of the AOI not specifically targeted during the acquisition. All discernible laser returns from the fall 2013 acquisition were processed to aid AKDGGS in assessing the topographic and geophysical properties of the study area to support storm monitoring.

Shaded relief images have been visually inspected for data errors such as pits, border artifacts, and shifting. LiDAR flight lines have been examined to ensure consistent elevation values across overlapping flight lines. The Root Mean Square Error (RMSE) of line to line relative accuracy for this dataset is 0.035 m. Please see the LiDAR data report for a discussion of the statistics related to this dataset.