2022 USGS Lidar: Mid-North, IL

LIDAR-derived binary (.las) files ASPRS version 1.4 format containing classified points of all returns. There are 11 classifications: Unclassified, Ground, Automated Low Veg [0.5-5 feet], Automated Medium Veg [5-20 feet], Automated High Veg [>20 feet], Automated Buildings, Low Noise, Water, Bridge Decks, High Noise and Ignored Ground (breakline proximity). The files are delivered in 2000 ft by 2000 ft tiles. These files adhere to the USGS-NGP Lidar Base Specification 2021 rev. A, Quality Level 2 (QL2) standards. The contractual aggregate nominal pulse spacing (ANPS) is less than or equal to 0.5 m. The contractual aggregate nominal point density (ANPD) is 4.0 points or greater per square meter.

This dataset covers approximately 9013 square miles in north central Illinois and consists of 4 deliveries or blocks.

IL_MidNorth_1 (Work Unit 229055) - Approximately 3410 square miles, including Fulton (partial), Henderson, Knox (partial), McDonough, Mercer, and Warren counties

IL_MidNorth_2 (Work Unit 300135) - Approximately 3161 square miles, including Fulton (partial), Knox (partial), Marshall, Peoria, Putnam, Stark, Tazewell, and Woodford counties

IL_MidNorth_3 (Work Unit 300136) - Approximately 2126 square miles, including DeWitt, McLean, and Platt counties

IL_MidNorth_4 (Work Unit 300137) - Approximately 369 square miles, including DuPage county

This metadata record 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 spring 2022 leaf-off and snow-free lidar survey over an Area of Interest (AOI) of approximately 9,013 square miles in central and northeastern Illinois. This Task Order will support the National Resources Conservation Service (NRCS) agricultural resource mapping and soil survey programs, and the 3DEP mission. The following will describe the proposed services and associated revised costs to successfully complete the mission.

USGS Task Order 140G0222F0045-IL_MidNorth_D22

Synthetic Points: Optech's Galaxy T2000 raw lidar post-processing software LMS uses a method to fill small voids with synthetic points when the PulseTRAK algorithm drops a point recording. This can happen between the transition of PIA (pulse-in-air) zones.

The following are the USGS lidar fields in JSON:

{

"ldrinfo" : {

"ldrspec" : "USGS-NGP Lidar Base Specification 2021, Revision A",

"ldrsens" : "Optech Galaxy T2000 Airborne Laser Terrain Mappers (ALTM) 5060475, 5060492 & 5060495",

"ldrmaxnr" : "8",

"ldrnps" : "0.5",

"ldrdens" : "4",

"ldranps" : "0.5",

"ldradens" : "4",

"ldrfltht" : "2585,3250",

"ldrfltsp" : "170",

"ldrscana" : "45,40",

"ldrscanr" : "98,69",

"ldrpulsr" : "1200,600",

"ldrpulsd" : "3.5",

"ldrpulsw" : "1.2925,1.625",

"ldrwavel" : "1064",

"ldrmpia" : "1",

"ldrbmdiv" : "0.25",

"ldrswatw" : "2141,2366",

"ldrswato" : "20,55",

"ldrgeoid" : "National Geodetic Survey (NGS) Geoid18"

},

"ldraccur" : {

"ldrchacc" : "0.26,0.32",

"rawnva" : "0.0",

"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" : "3",

"clasitem" : "Low Vegetation (0-3m; automated only)"

},

"lasclass" : {

"clascode" : "4",

"clasitem" : "Medium Vegetation (3-7m; automated only)"

},

"lasclass" : {

"clascode" : "5",

"clasitem" : "High Vegetation (greater than 7m; automated only)"

},

"lasclass" : {

"clascode" : "6",

"clasitem" : "Buildings (automated only)"

},

"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.

The lidar data set was produced to meet ASPRS Positional Accuracy Standards for Digital Geospatial Data (2014) for a 30 (cm) RMSEx / RMSEy Horizontal Accuracy Class which equates to Positional Horizontal Accuracy = +/- 73.4 cm at a 95% confidence level.

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) = 4.27 cm RMSE

Vegetated Vertical Accuracy (VVA) = 15.27 cm at 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 NOAA Office for Coastal Management (OCM) ingested references to the USGS Entwine Point Tile (EPT) files hosted on Amazon Web Services (AWS) into the Digital Coast Data Access Viewer (DAV). The DAV accesses the point cloud as it resides on AWS under the usgs-lidar-public-container.