2021 USGS/NRCS Lidar: Delta Junction, AK

LIDAR-derived binary (.las) files containing classified points of all returns. We have seven (7) classifications Unclassified, Ground, Low Noise, Water, Bridge Decks, High Noise and Ignore Ground. These files adhere to USGS-NGP Lidar Base Specification 2020 rev. A Quality Level 2 (QL2) standards, two points or greater per square meter.

This metadata supports the data entry in the NOAA Digital Coast Data Access Viewer (DAV). For this data set, the DAV is leveraging the Entwine Point Tiles (EPT) hosted by USGS on Amazon Web Services.

This task is for providing a high-resolution QL2 lidar survey in late summer 2021 over an area of approximately 1,261 square

miles in southeast Alaska in and around Delta Junction, which includes portions of Fairbanks North Star and Southeast

Fairbanks Boroughs. This project will support the Natural Resource Conservation Service (NRCS), and the 3DEP mission. The project has 1622 tiles (1500x1500m).

USGS Task Order 140G0221F0235-AK_DeltaJunction_2021_D21

Project dates have been converted from Coordinated Universal Time (UTC) to Alaska Standard Time (GMT-9).

The following are the USGS lidar fields in JSON:

{

"ldrinfo" : {

"ldrspec" : "USGS-NGP Base Lidar Specification 2020 Rev A",

"ldrsens" : "Optech Galaxy T2000 Airborne Laser Terrain Mappers (ALTM) 5060449",

"ldrmaxnr" : "8",

"ldrnps" : "0.7",

"ldrdens" : "2",

"ldranps" : "0.7",

"ldradens" : "2",

"ldrfltht" : "2470",

"ldrfltsp" : "170",

"ldrscana" : "35",

"ldrscanr" : "69",

"ldrpulsr" : "400",

"ldrpulsd" : "3.5",

"ldrpulsw" : "0.7904",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.25",

"ldrswatw" : "1558",

"ldrswato" : "20",

"ldrgeoid" : "National Geodetic Survey (NGS) Geoid12B"

},

"ldraccur" : {

"ldrchacc" : "0",

"rawnva" : "0",

"rawnvan" : "0"

},

"lasinfo" : {

"lasver" : "1.4",

"lasprf" : "6",

"laswheld" : "Withheld (ignore) points were identified in these files using the standard LAS withheld bit.",

"lasolap" : "Swath "overage" points were not identified in these files using the standard LAS overlap bit.",

"lasintr" : "12",

"lasclass" : {

"clascode" : "1",

"clasitem" : "Unclassified"

},

"lasclass" : {

"clascode" : "2",

"clasitem" : "Ground"

},

"lasclass" : {

"clascode" : "7",

"clasitem" : "Low Noise"

},

"lasclass" : {

"clascode" : "9",

"clasitem" : "Water"

},

"lasclass" : {

"clascode" : "17",

"clasitem" : "Bridge"

},

"lasclass" : {

"clascode" : "18",

"clasitem" : "High Noise"

},

"lasclass" : {

"clascode" : "20",

"clasitem" : "Ignore Breakline"

}

}}

Any conclusions drawn from the analysis of this information are not the responsibility of NOAA, the Office for Coastal Management or its partners.

Data is available online for bulk and custom downloads.

None

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.

This data set was produced to meet ASPRS Positional Accuracy Standard for Digital Geospatial Data (2014) for a 10-cm RMSEz Vertical Accuracy Class.

USGS Determined Vertical Accuracy

Non-Vegetated Vertical Accuracy (NVA) = 4.8 cm RMSE

Vegetated Vertical Accuracy (VVA) = 24.61 cm at the 95th Percentile

These LAS data files include all data points collected. No points have been removed or excluded. A visual qualitative assessment was performed to ensure data completeness. No void areas or missing data exist. The raw point cloud is of good quality and data passes Non-Vegetated Vertical Accuracy specifications.

Data covers the entire area specified for this project.

Data is backed up to tape and to cloud storage.

The Delta Junction, AK lidar was ingested into the Data Access Viewer for custom product generation by leveraging USGS hosted Entwine Point Tiles.