Natural Resources Conservation Service (NRCS), United States Geological Survey (USGS),Illinois States Geological Survey (ISGS), Aerial Services Inc. 20210722 grid These acquisitions of the LiDAR data and its derivatives were made possible by funding from NRCS and USGS. The final digital surface model was produced by ISGS after their QAQC process on the delivered data from ASI. There were some raster errors that were cleaned up within this process and noted errors in the classified las tiles data collection, these errors were reported and planned to be corrected. The contracted product acquired included: bare earth hydro-flattened DEMs .img files, hydro breaklines, processed Classified LAS 1.4 files, intensity images, along with vendor provided metadata and vertical accuracy reports. Geographic Extent: Jo Daviess, Stephenson, Carroll, Ogle, Whiteside, Lee, Rock Island, and Henry Counties Illinois, covering approximately 5318 square miles. Dataset Description: Illinois 8 county 2019 Lidar Dataset Description: Block 3_IL_8 County, Illinois 2019 Lidar project called for the planning, acquisition, processing and derivative products of lidar data to be collected at a nominal pulse spacing of 0.5 meter. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification, Version 1.3. The data was developed based on a horizontal projection/datum of NAD83(2011), State Plane Coordinat System Illinois West (FIPS 1202), United States Survey Feet, and a vertical datum of NAVD88 (GEOID12B), US survey feet. Lidar data was delivered as processed Classified LAS 1.4 files, formatted to 37,739 individual 2000 US survey feet x 2000 US survey feet tiles, and 37,738 tiled Intensity Imagery, and 37,739 tiled bare earth DEMs; all tiled to the same 2000 US survey feet x 2000 US survey feet schema. Tile 2075_1735 is located within a water body with no reflectance measured within the tile boundary, so no intensity image was produced for that tile. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification, Version 1.3; Quality Level 2+. The data was developed based on a horizontal projection/datum of NAD83(2011), State Plane Coordinat System Illinois West (FIPS 1202), US survey feet, and a vertical datum of NAVD88 (GEOID12B), US survey feet. Lidar data was delivered as processed Classified LAS 1.4 files, formatted to 37,739 individual 2000 US survey feet x 2000 US survey feet tiles, as tiled Intensity Imagery, and as tiled bare earth DEMs; all tiled to the same 2000 x 2000 US survey feet schema. Ground Conditions: Lidar was collected in late 2019, early 2020 and late 2020 while no snow was on the ground, and rivers levels fluctuated. In order to post process the lidar data to meet task order specifications and meet ASPRS vertical accuracy guidelines, Subcontractor, Surveying and Mapping, LLC (SAM) established a total of 76 ground control points that were used to calibrate the lidar to known ground locations established throughout the Block 3_IL_8 County project area. An additional 219 independent accuracy checkpoints, 127 in Bare Earth and Uraban landcovers (127 NVA points), 92 in tall Grass/tall weeds/crops, Brush lands/short trees, Forested categories (92 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 for use in conservation planning design, research, floodplain mapping, dam safety assessment and elevation modeling, ect. 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. G17PC00007 CONTRACTOR: Aerial Services, Inc. Lidar data were acquired and calibrated by the prime contractor. PRIME: Aerial Services, Inc. All follow-on processing was completed by the prime contractor. Subcontractor, Surveying and Mapping, LLC (SAM) established a total of 76 ground control points that were used to calibrate the lidar to known ground locations established throughout the Block 3_IL_8 County project area. U.S. Geological Survey (USGS) - National Geospatial Program (NGP) Lidar Base Specification v1.3 Leica ALS70-HP 4 0.5 4 0.5 4 1300 125 50 47 394 4 0.76 1064 1 0.28 1212 30 National Geodetic Survey (NGS) Geoid12B U.S. Geological Survey (USGS) - National Geospatial Program (NGP) Lidar Base Specification v1.3 Riegle LMS-Q1560 6 0.5 4 0.5 4 1500 130 60 89 400 2.5 0.75 1064 1 0.28 1725 30 National Geodetic Survey (NGS) Geoid12B U.S. Geological Survey (USGS) - National Geospatial Program (NGP) Lidar Base Specification v1.3 Optech Galaxy Prime 8 0.5 4 0.5 4 1829 150 40 85 400 2.5 0.75 1064 1 0.28 1331 30 National Geodetic Survey (NGS) Geoid12B 0.231 0.098 76 1.4 6 Withheld (ignore) points were identified in these files using the standard LAS witheld 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 20191123 20201112 ground condition Complete None Planned -91.09201 -88.90847 42.51892 41.13218 2047110 2635812 2131621 1628721 None Model LAS Point Cloud Remote Sensing Elevation Data Lidar None Illinois Jo Daviess Country Stephenson County Carroll County Ogle County Whiteside County Lee County Rock Island County Henry County No restrictions apply to these data. ISGS information is the property of and copyrighted by the Board of Trustees of the University of Illinois with all rights reserved. University copyright policy is stated in the General Rules Concerning University Organization and Procedure, Article III, Section 4. A link is provided in the Cross References section. Individuals or entities may make fair use of copyrighted ISGS material, such as reproducing a single figure or table, or using a brief text quotation, without obtaining formal permission, but in all cases the Illinois State Geological Survey must be credited as the source of the material. To reproduce ISGS information beyond the fair use standard, permission must be obtained from the ISGS Information Office, 615 East Peabody Drive, Champaign, Illinois 61820, 217-333-4747, isgs@isgs.illinois.edu. License fees and a license agreement may be required, depending on the proposed usage. Any use of these data is governed by University and campus policies, in particular, but not limited to, the Policy on Appropriate Use of Computers and Network Systems at the University of Illinois at Urbana-Champaign, the ISGS Terms of Use document available at the ISGS Web site, and the University of Illinois Web Privacy Notice. Links to these are provided in the Cross References section. Map information is to be used at a scientifically and cartographically appropriate scale, that is, at a scale no greater than indicated on the map or as described in the documentation of the map or map data. Map information is not appropriate for, and is not to be used as, a geodetic, legal, or engineering base. Map information has no legal basis in the definition of boundaries or property lines and is not intended as a substitute for surveyed locations such as can be determined by a registered Public Land Surveyor. The data do not replace the need for detailed site-specific studies.. However, 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. Natural Resources Conservation Service (NRCS), United States Geological Survey (USGS),Illinois States Geological Survey (ISGS), Aerial Services Inc. Waypoint's Inertial Explorer version 8.60; Leica's CloudPro version 1.2.4; Applanix PosPac 8.2; RiProcess; RiAnalyze; Optech’s LMS; BayesMap-StripAlign; MicroSatation Connect version 10.14.02.01; TerraSolid TerraMatch version019.002,TerraModel version 019.008, TerraScan version 019.008; Windows 10 Operating \\server\directory path\*.las 3.36TB Data covers the entire area specified for this project. ASI: 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. ISGS QAQC findings: 1-The VVA checkpoints included in the geodatabase delivery have erroneous Z values. 2-Observation: The checkpoints were delivered in the Contiguous USA Albers projection with Z values in meters instead of the projection and units of measurement the rest of the data was in. (2011 IL SPW \ feet). 3-On tile #2239_1695 there is a house that has been misclassified as ground. (Has been fixed in the final derivatives). 4-Almost all of the buildings have been classified as vegetation. Since there was no building classification buy up, they should still be classified as class 1, unclassified. This data set was produced to meet ASPRS Positional Accuracy Standard for Digital Geospatial Data (2014) for a 10-cm RMSEz Vertical Accuracy Class. 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 resultsmet the project specifications. 4) Once all lifts were completed with individual boresight adjustment, the technicians checked and corrected the vertical mis alignment 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. LAS Point Classification QL2+: The point classification was performed as described below. Classification Filters were applied to aid in the definition of; terrain characteristics, vegetation attribution of low, medium or high and building roof tops. Filtering processes address aspects of the data such as: ground points, noise points, air points, low points, Low vegetation 0.5-5’, medium vegetation 5-20’, high vegetation >20’, manmade features, buildings, and overlap points. 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 v019.008 was used to identify the 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. 20210721 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. 20210216 ISGS Secondary Processing: 1. Thorough QAQC check was completed to ensure and evaluate the quality of the data delivered and that all the specifications have been met in accordance to the contract and national specifications set for LiDAR data. 2. Through ArcGIS 10.8 the following steps were completed to created Terrain and hillshade products: a. LAS to Mulitpoint conversion using 3D analyst tools.ASPRS Classifications were used below:1-Unclassified 2-Ground 3-Low Vegetation 4-Medium Vegetation 5-High Vegetation 7-Low Noise 9-Water 17-Bridge Decks 18-High Noise 20-Ignored Ground. b. Terrains are then created and pyramids are calculated. c. Terrain to Raster tool was used in 3D Analyst. The parameters of data type float, natural neighbors method, sampling distance is cell size and the point spaceing value from the LiDAR data. d. Hillshades are created from the above rasters with a Z value of 2. 3. These derivatives were checked again visually for errors. If any errors were perceived corrections were performed in the derivative products. If other errors were perceived these were communicated with the vendor. 4. When product was finalized then metadata was completed before making data available. IL_8cty_lidar_gnd_ctrl 20220124 Point Point 119,347,163,080 State Plane Coordinate System 1983 NAD 1983 2011 Illinois West State Plane (FIPS 1202) 0.999975 -88.33333333 36.66666667 984250 0.0 row and column 2 2 US Survey Feet North American Datum of 1983 2011 Geodetic Reference System 1980 6378137 298.25722101 North American Vertical Datum of 1988, Geoid 12B 0.01 US survey feet Explicit elevation coordinate included with horizontal coordinates 20220124 Illinois State Geological Survey (ISGS) mailing and physical

615 E. Peabody Dr.

Champaign IL 61820 USA (217)333-4747 FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998 None. None. None. Unclassified. None. None. None. IL_Rock_Island_DSM_2020