Data Management Plan

The University of Alaska Fairbanks, Geographic Information Network of Alaska (UAF/GINA) provided Aero-Metric, Inc. (AeroMetric) and Watershed Sciences, Inc. (WSI) with detailed specifications for this project in the spring of 2013. Planning and acquisition of airborne LiDAR data was carried out by WSI in early May of 2013.

This delivery contains point cloud data in LAS 1.2 format classified in the following manner:

Class 1: Unclassified

Class 2: Bare Earth Ground

Class 3: Low Vegetation (vegetation within 12 inches of the ground surface)

Class 4: Medium Vegetation (vegetation greater than 12 inches, but less than 36 inches above the ground surface)

Class 5: High Vegetation (vegetation greater than 36 inches above the ground surface)

Class 6: Buildings

Class 7: Noise

Class 8: Ground Model Keypoints

Class 9: Water

Class 10: Breakline Proximity

Class 14: Bridge Decks

The following are the collection parameters and equipment used to create these data sets:

Aircraft: Cessna Caravan (N604MD)

LiDAR System: Leica ALS60

Approximate Collection Altitude (Above Mean Terrain): 900 meters

Ground Speed: 160 kts

Pulse Rate Frequency: 98-106 kHz

Mirror Scan Frequency: 66 Hz

Scan Angle (+/-): 14 degrees

Accuracy statements are based on areas of moderate terrain, with points classified as ground. 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, derived products may be less accurate in areas of extreme terrain and dense vegetation due to a lesser number of points defining the ground in these areas. Classified data sets such as this one may have varying posting due to some pulses not reaching the ground.

The NOAA Office for Coastal Management (OCM) downloaded this lidar data from the AK DGGS site (https://elevation.alaska.gov/) and processed the data to be available on the Digital Coast Data Access Viewer (DAV). OCM processed all points to the Digital Coast Data Access Viewer (DAV).

Process Steps:

• 2013-05-31 00:00:00 - WSI created a smoothed-best estimated trajectory (SBET) of the sensor at a rate of 200 Hz, by integrating the airborne GPS and IMU data The basis of the GPS coordinates were two dual frequency GPS receivers, collecting data at a rate of 2 Hz operated by Aero-Metric during the acquisition phase of this project, and were referenced to NAD83 (CORS96) ellipsoid heights.
• 2013-06-03 00:00:00 - WSI integrated SBET and raw laser data to produce point cloud data in LAS 1.2 format for each flight line.
• 2013-06-12 00:00:00 - WSI processed data calibration: An in-situ calibration was performed using the data collect for this project. The data was classified in each line separately for ground and other common features between lines, such as building roofs. This data was processed in TerraMatch 11.001 (TerraSolid, Ltd.), to compute corrections for roll, pitch, heading, and mirror scale. These corrections are applied in order to minimize discrepancies between flight lines.
• 2013-06-13 00:00:00 - WSI automated classification of the bare-earth data from the LiDAR point cloud using a series of algorithms customized for the types of terrain encountered in the project.
• 2013-06-20 00:00:00 - WSI manually classified any data which appears to be improperly classified using the automated methods.
• 2013-06-25 00:00:00 - WSI provided AeroMetric with calibrated, vertically adjusted, and classified LiDAR data in the Vallenar Bay area.
• AeroMetric completed a series of evaluations including verifying density requirements, confirming relative and absolute accuracies, reviewing coverage and classification's, and confirming the reproducibility of ranges within the LiDAR Data.
• 2013-09-09 00:00:00 - Due to tiling artifacts being identified in the low vegetation and high vegetations, using a automated method those classes were properly re-classified.
• Create point cloud data, by tile in LAS 1.2 format.
• 2018-09-10 00:00:00 - The NOAA Office for Coastal Management (OCM) downloaded 32 laz files from the Alaska Division of Geological and Geophysical Surveys data Portal (https://elevation.alaska.gov/). The files contained classified elevation and intensity measurements for the 2013 Vallenar Bay data set. The data were in Alaska State Plane, Zone 5001 coordinates (NAD83 2011, US survey feet) and NAVD88 elevations (GEOID12A) in feet. The data were classified: Class 1: Unclassified, Class 2: Bare-earth ground, Class 3: Low vegetation, Class 4: Medium Vegetation, Class 5: High Vegetation, Class 6_ Buildings, Class 7: Noise, Class 8: Ground Model Keypoints, Class 9: Water, Class 10: Breakline Proximity, Class 14: Bridge Decks. Low vegetation is defined in the report as vegetation within 12 inches of the ground surface, medium vegetation as vegetation greater than 12 inches, but less than 36 inches above the ground surface and high vegetation as vegetation greater than 36 inches above the ground surface. OCM processed all points to the Digital Coast Data Access Viewer (DAV). OCM performed the following processing on the data for Digital Coast storage and provisioning purposes: 1. The LAStools software scripts lasinfo and lasvalidate were run on the laz files to check for errors. 2. An internal OCM script was run to check the number of points by classification and by flight ID and the gps times and intensity ranges. 3. Internal OCM scripts were run on the laz files to convert from Alaska State Plane, Zone 5001 coordinates to geographic coordinates, to convert from NAVD88 elevations to ellipsoid elevations using the GEOID12A model, to convert from feet to meters, to assign the geokeys, to assign a lidar domain profile, to sort the data by gps time and zip the data to database and to http.

Data is available online for custom and bulk downloads.