Aerial Services, Inc. 20220126 Lidar point cloud Product: These lidar data are processed Classified LAS 1.4 files, formatted to 22,802 individual 2000 US survey feet x 2000 US survey feet tiles; used to create intensity images, 3D breaklines and hydro-flattened DEMs as necessary. Geographic Extent: USGS_IL_SouthCentral_2_2021 Illinois, covering approximately 3,260 square miles. Dataset Description: USGS_IL_SouthCentral_2_2021 Illinois 2021 Lidar project called for the planning, acquisition, processing and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.5 meters. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification, Version 2020 rev A. The data was developed based on a horizontal projection/datum of NAD83(2011), State Plane Illinois West, US survey feet, and a vertical datum of NAVD88 (GEOID18), US survey feet. Lidar data was delivered as processed Classified LAS 1.4 files, formatted to 22,823 individual 2000 US survey feet x 2000 US survey feet tiles, 22,802 LAS files,as was tiled Intensity Imagery, and 22,823 tiled bare earth DEMs; all tiled to the same 2000 US survey feet x 2000 US survey feet schema. Lidar point cloud LAS files are created for each tile in the tiling schema in which there is reflected photonic energy. No LAS files are created for tiles in which there is total absorption of photons, such as tiles consisting of all water and in which photonic energy is absorbed. LAS files affected by photonic energy absorption are; 2555_7590, 2539_7210, 2539_7230, 2543_7190, 2543_7230, 2545_7230, 2545_7310, 2545_7330, 2547_7310, 2547_7330, 2547_7350, 2547_7370, 2547_7410, 2549_7330, 2549_7390, 2549_7410, 2551_7330, 2551_7350, 2551_7370, 2551_7410, 2555_7370. Intensity Images are created for each tile in the tiling schema in which there is reflected photonic energy. No intensity tiles are created for tiles in which there is total absorption of photons, such as tiles consisting of all water and in which photonic energy is absorbed. Stack emissions are present in the USGS_IL_SouthCentral_2_2021 project area, affecting tiles 2441_5890, 2441_5870, 2439_5870. These obscured areas are the result of aerosol clouds emitting from a plant and the LiDAR pulses were absorbed by the clouds. ISGS QAQC Review: There were several mis classified points that were reported to the vendor ASI and the vendor choose not to correct those. As a result, the above ground points are not reliable. Ground Conditions: Lidar was collected in spring 2021, while no snow was on the ground and rivers were at or below normal levels. In order to post process the lidar data to meet task order specifications and meet ASPRS vertical accuracy guidelines, Subcontractor, Prairie Engineers established a total of 156 ground control points that were used to calibrate the lidar to known ground locations established throughout the USGS_IL_SouthCentral_2_2021, Illinois project area. An additional 156 independent accuracy checkpoints, 88 in Bare Earth and Uraban landcovers (88 NVA points), 68 in tall Grass/tall weeds/crops, Brush lands/short trees, Forested categories (68 VVA points), were used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data. To acquire QL2+ lidar detailing surface elevation data, and vegetation to support the Federal Emergency Management (FEMA) Risk Mapping, Assessment, and Planning (MAP) program, the National Resources Conservation Service (NRCS) high resolution elevation enterprise program, the Illinois State Geological Survey’s Height Modernization Program, Land Stewardship (IDALS) Illinois Flood Plain program, and the 3DEP mission. Classified LAS files are used to show the manually reviewed bare earth surface. This allows the user to create Intensity Images, Breaklines and Raster DEMs. The purpose of this lidar data was to produce high accuracy 3D hydro-flattened Digital Elevation Model (DEM) with a 2 US survey feet cell size. These lidar point cloud data were used to create intensity images, 3D breaklines, and hydro-flattened DEMs as necessary. USGS Contract No. 140G0221F0069 CONTRACTOR: Aerial Services, Inc. (ASI) served as the prime contractor for this project. In addition to project management, ASI was responsible for bare earth cleanup, and hydro collection for 711 square miles of the western most section of the USGS_IL_SouthCentral_2_2021 project area. ASI produced the LiDAR products; Digital Elevation Model (DEM) production, Intensity Image production, and quality assurance for the entire USGS_IL_SouthCentral_2_2021 project area. Subcontractor: Aerial Surveys International, LLC was responsible for LiDAR acquisition and calibration for a total of 1091 square miles of the northern section of the USGS_IL_SouthCentral_2_2021project area. Subcontractor: SurvTech Solutions was responsible for LiDAR acquisition and calibration for 2169 square miles of the southern section of the USGS_IL_SouthCentral_2_2021 project area. Subcontractor: Subcontractor: Ayres Associates manually performed bare earth cleanup, and collected hydro on the remaining 2549 square mile area of the USGS_IL_SouthCentral_2_2021 project area. All follow-up processing was completed by the prime contractor. U.S. Geological Survey (USGS) - National Geospatial Program (NGP) Lidar Base Specification v2020, Revision A Optech Galaxy T2000 8 0.5 4 0.5 4 2500 160 32 92 800 1.25 0.37 1064 1 0.16 1434 30 National Geodetic Survey (NGS) Geoid18 U.S. Geological Survey (USGS) - National Geospatial Program (NGP) Lidar Base Specification v2020, Revision A Optech T2000 8 0.5 4 0.5 4 2134 160 32 92 800 1.25 0.24 1064 1 0.16 1553 30 National Geodetic Survey (NGS) Geoid18 0.64 0 0 1.4 6 Withheld (ignore) points were identified in these files using the standard LAS withheld bit. Swath "overage" points were identified in these files using the standard LAS overlap bit 16 1 Processed, but Unclassified 2 Bare Earth Ground 3 Low Vegetation 4 Medium Vegetation 5 High Vegetation 7 Low Noise 9 Water 17 Bridge Decks 18 High Noise 20 Ignored Ground 20210307 20210412 ground condition Complete None Planned -90.94023389 -89.09291646 39.40735527 37.55742244 2078000 2600000 998000 326000 None Model LAS Point Cloud Remote Sensing Elevation Data Lidar None Illinois Bond Calhoun Clinton Jackson Jersey Perry Washington No restrictions apply to these data. ISGS data review comments: Users should be aware that above ground points may not be complete in certain areas. This was discovered after the contract was closed and no resolution was provided by the vendor ASI. An automated filtration process was used to classify points above ground, some or most of the buildings were left in the vegetation class and should be classified as unclassified as the buildings classification was not paid for by the funding partners (was ASI response). Users should be aware that temporal changes may have occurred since this dataset was collected and that some parts of these data may no longer represent actual surface conditions. Users should not use these data for critical applications without a full awareness of its limitations. Acknowledgement of the U.S. Geological Survey would be appreciated for products derived from these data. Track’Air; Topoflight ; Optech’s FMS; Trimble CenterPoint® RTX™, POSPac PP-RTX, GNSS, Applanix’s POSPAC MMS version 8.4.7284.36831, Optech’s LMS ; MARS 8; RIPROCESS; BayesMap-StripAlign; MicroSatation Connect Update 16 - version 10.16.00.80; TerraSolid TerraMatch version020.003,TerraModel version 021.004, TerraScan version 021.005; Windows 10 Operating \\server\directory path\*.las 2.56TB Data covers the entire area specified for this project. 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. This data set was produced to meet ASPRS Positional Accuracy Standards for Digital Geospatial Data (2014) for a ___ (cm) RMSEx / RMSEy Horizontal Accuracy Class which equates to Positional Horizontal Accuracy = +/- ___ cm at a 95% confidence level. The boresight for each lift was done individually as the solution may change slightly from lift to lift. The following steps describe the Raw Data Processing and Boresight process: 1) Technicians processed the raw data to LAS format flight lines using the final GPS/IMU solution. This LAS data set was used as source data for boresight. 2) Technicians first used Aerial Services Inc. proprietary and commercial software to calculate initial boresight adjustment angles based on sample areas selected in the lift. These areas cover calibration flight lines collected in the lift, cross tie and production flight lines. These areas are well distributed in the lift coverage and cover multiple terrain types that are necessary for boresight angle calculation. The technician then analyzed the results and made any necessary additional adjustment until it is acceptable for the selected areas. 3) Once the boresight angle calculation was completed for the selected areas, the adjusted settings were applied to all of the flight lines of the lift and checked for consistency. The technicians utilized commercial and proprietary software packages to analyze how well flight line overlaps match for the entire lift and adjusted as necessary until the results met the project specifications. 4) Once all lifts were completed with individual boresight adjustment, the technicians checked and corrected the vertical misalignment of all flight lines and also the matching between data and ground truth. The relative accuracy was less than or equal to 6 cm RMSEz within individual swaths and less than or equal to 8 cm RMSEz or within swath overlap (between adjacent swaths). 5) The technicians ran a final vertical accuracy check of the boresighted flight lines against the surveyed check points after the z correction to ensure the requirement of NVA = 19.6 cm 95% Confidence Level (Required Accuracy) was met. Point classification was performed according to USGS Lidar Base Specification 1.4, and breaklines were collected for water features. Bare earth DEMs were exported from the classified point cloud using collected breaklines for hydroflattening. USGS South Central IL Survey 2021 20210804 LAS Point Classification:  The point classification was performed as described below.  Classification Filters were applied to aid in the definition of; terrain characteristics, and vegetation attribution to low, medium, or high.  Filtering processes address aspects of the data such as ground points, noise points, air points, low points, manmade features,  and setting withheld and overlap bitset.   The automated filtration defined: Low Vegetation at 0.5-5 feet, Medium Vegetation at 5-20 feet, and High Vegetation at >20 feet by distance from the ground. Classifying low vegetation to class code 3, medium vegetation to class code 4, and high vegetation to class code 5 respectively.  These vegetation classes represent all non-noise points that fall into the distances above the ground surface, and will likely include buildings, utility poles, powerlines, and other infrastructure.  The Classified point cloud data was manually reviewed to ensure correct classification of; ground (ASPRS class 2).  After the bare earth surface was finalized, it was then used to generate all hydro-breaklines through heads-up digitization.  All ground (ASPRS class 2) lidar data inside of the Inland Ponds and Lakes, and Inland Streams and Rivers are classified to water (ASPRS class 9).  A buffer of 2.5 feet was used around each hydro-flattened feature to classify ground (ASPRS class 2) to ignored ground (ASPRS class 20).  Island features were checked to ensure that Ground point (ASPRS class 2) remained classified as Ground.  Ground points (ASPRS class 2) within 2.5 feet of bridge breaklines, used to reduce triangulation between bridge decks were also classified to Ignored ground (ASPRS class 20).  All bridge decks were classified to Bridge deck (ASPRS class 17).  All remaining points were filtered, or manually classified to their respective point classification; processed (ASPRS class 1), low vegetation (ASPRS class 3), medium vegetation (ASPRS class 4), high vegetation (ASPRS class 5), low noise (ASPRS class 7), high noise (ASPRS class 18).  TerraScan version 021.005 was used to identify the withheld and overlap flag and bit set flags to LAS v1.4 specifications. LP360 64bit was used to deduce the Well Known Text (WKT) and an ASI proprietary software was used to format the LAS to the final LAS v1.4 Format 6 version. LAStools by rapidlasso GmbH, open source, lasvalidate (open source LGPL) and an ASI proprietary software was used to perform final analysis to checks on LAS header information, LAS point classes, and LAS timestamps. 20220125 Data was tested at 0.5 meter nominal pulse spacing and a 4 pulses per meter. The nominal pulse spacing was tested on classified tiled LAS using geometrically reliable first-return points. NPS was tested using Delaunay Triangulation that produced average point spacing between all nearest neighbors. 20210804 Point Point 83,028,275,596 State Plane Coordinate System 1983 NAD 1983 2011 Illinois West State Plane (FIPS 1202) 0.999941 -90.16666666666667 36.66666667 2296583 0.0 coordinate pair 0.01 0.01 US survey feet North American Datum of 1983 2011 Geodetic Reference System 1980 6378137 298.257222101 North American Vertical Datum of 1988, Geoid 18 0.01 US survey feet Explicit elevation coordinate included with horizontal coordinates 20220126 Aerial Services, Inc. mailing and physical

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Cedar Falls IA 50613 USA (319)277-0436 FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998 None. None. None. Unclassified. None. None. None. IL_Washington_DSM_2021