Merrick & Co 2020 las data Project Project Greenwood Village, CO Merrick & Co LIDAR-derived binary (.las) files ASPRS ver 1.4 format containing classified points of all returns. We have 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 Ignore Ground (breakline proximity). Model key points are bit-flagged and created from ground (class = 2) points using a five foot horizontal and a 0.2 foot vertical variance. The files are delivered in 2000ft by 2000ft tiles. These files adhere to the USGS-NGP Lidar Base Specification, Version 2.1 Quality Level 2 (QL2) standards. The contractual aggregate nominal pulse spacing (ANPS) is less than or equal to 0.5m. The contractual aggregate nominal point density (ANPD) is 4.0 points or greater per square meter. U20125: LiDAR 2020-Data Processing of 5 Counties in Wabash & Embarras Basin - The required Professional Services include the data processing of existing high fidelity Light Detection and Ranging (LiDAR) data for Clark, Coles, Cumberland, Douglas & Edgar Counties in Illinois in 2020. As a result of the supplemental funding from the USGS 3DEP program, the revised project area comprises of approximately 2,576.45 square miles (i.e., increase from 2,505.02). Data processing services include LiDAR classification; hydro-flattening; QA/QC, and; development of derivative deliverable products (including metadata). USGS-NGP Base Lidar Specification v2.1 Optech Galaxy Prime Airborne Laser Terrain Mappers (ALTM) 5060380 8 0.5 4 0.5 4 1750 170 42 95 700 3.5 0.875 1064 1 0.25 1344 20 National Geodetic Survey (NGS) Geoid12B 0.19 0.090 79 0.090 79 0.128 61 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 by a separate bit flag. 12-bit 1 Undetermined/Unclassifed 2 Ground 3 Low Veg 4 Medium Veg 5 High Veg 6 Building 7 Low point (noise) 9 Water 17 Bridge Decks 18 High Noise 20 Ignore ground (near a breakline) 20200408 unknown 20200503 unknown ground condition Complete Unknown -88.4921872826289 -87.5088173452966 39.898039587277 39.1296992564673 939502.627035539 1216501.00449645 1177614.82487463 897676.644188874 none LIDAR DEM Intensity none Illinois Wabash Basin Embarrass Basin none 2020 none unknown Sheena Beaverson Illinois State Geological Survey Program Manager mailing and physical address

615 E. Peabody Drive

Champaign IL 61820 217-244-9306 sbeavers@illinois.edu Please refer to the distribution information section. Microsoft Windows 7 Professional Service Pack 1; ESRI ArcCatalog 10.7.1 The dataset was captured, attributed, and reviewed to ensure completeness and accuracy of at least 95%. The dataset was captured, attributed, and reviewed to ensure completeness and accuracy of at least 95%. The dataset was captured, attributed, and reviewed to ensure completeness and accuracy of at least 95%. This data set was produced to meet ASPRS Positional Accuracy Standards for Digital Geospatial Data (2014) for a 19(cm) RMSEx / RMSEy Horizontal Accuracy Class which equates to Positional Horizontal Accuracy = +/-46.5cm at a 95% confidence level. This data set was tested to meet ASPRS Positional Accuracy Standard for Digital Geospatial Data (2014) for a 10-cm RMSEz Vertical Accuracy Class. Actual NVA accuracy was found to be RMSEz = 4.6cm, equating to +/- 9.0cm at the 95% confidence level. Actual VVA accuracy was found to be +/- 12.8cm at the 95th percentile. 0.009 Classified Non-Vegetated Vertical Accuracy (NVA) tested 0.009 meters vertical accuracy at the 95 percent confidence level. Seventy-nine (79) NVA points were used and validated against the DEM. 0.128 Classified Vegetated Vertical Accuracy (VVA) tested 0.128 meters vertical accuracy at the 95th percentile. Sixty-one (61) VVA points were used and validated against the DEM. JUNEAU Associates, Inc., P.C. 2020 Unknown tabular digital data ground control ground control Granite City, IL JUNEAU Associates, Inc., P.C. disc 2020 publication date ground control control point network to establish horizontal and vertical accuracy Merrick & Co 2020 LAS data LiDAR LiDAR Greenwood Village, Co. Merrick & Co disc 20200408 unknown 20200503 unknown ground condition LiDAR Surface returns used to create surface models. Classifed lidar: LIDAR data was collected using the Optech Galaxy sensor. The raw data was verified in MARS software for complete coverage of the project area, and boresighted to align the flightlines. Raw data files were parsed into manageable client-specific tiles. These tiles were then processed through automated filtering that separates the data into different classification groups: unclassified points, ground points, 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 ignore ground (breakline proximity). The data was next taken into MARS to reclassify the erroneous points that may remain in the LIDAR point cloud after auto filter. Four points or greater per square meter (QL2) ASPRS ver 1.4 format. ground control LiDAR 20201123 Doug Jacoby Merrick & Co Project Manager mailing and physical address

5970 Greenwood Plaza Blvd

Greenwood Village Co 80111 USA 303-353-3903 doug.jacoby@merrick.com Breaklines: Using MARS software hydro-flattened breaklines (rivers greater than 100 feet wide and waterbodies greater than two square acres and islands greater than one acre) were compiled. Additionally breaklines were placed underneath bridges and on waterfalls where necessary. MARS software using Intensity values and 3d elevations generates ESRI shape files which are then imported into an ESRI gdb for a project wide delivery. Monotonicity checks where validated (water flowing downstream). ground control LiDAR 20201123 Doug Jacoby Merrick & Co Project Manager mailing and physical address

5970 Greenwood Plaza Blvd

Greenwood Village Co 80111 USA 303-353-3903 doug.jacoby@merrick.com DEM: Using MARS software a two-foot (2ft) DEM GeoTIFF .tif files were created using the ground classified lidar points along with the breaklines. The files are delivered in 2000ft by 2000ft tiles. ground control LiDAR 20201123 Doug Jacoby Merrick & Co Project Manager mailing and physical address

5970 Greenwood Plaza Blvd

Greenwood Village Co 80111 USA 303-353-3903 doug.jacoby@merrick.com Intensity: Using MARS software a two-foot (2ft) Intensity GeoTIFF .tif files were created using the Intensity values of all returns minus the overlap points. The files are delivered in 2000ft by 2000ft tiles. These files are 8bit unsigned integers. ground control LiDAR 20201123 Doug Jacoby Merrick & Co Project Manager mailing and physical address

5970 Greenwood Plaza Blvd

Greenwood Village Co 80111 USA 303-353-3903 doug.jacoby@merrick.com Vector NAD_1983_2011_StatePlane_Illinois_East_FIPS_1201_Ft_US 0.999975 -88.333333 36.666667 984250.000000 0.000000 coordinate pair .001 .001 survey feet D_NAD_1983_2011 Geodetic Reference System 80 6378137.000000 298.257222 North American Vertical Datum of 1988 GEOID12B 0.000100 feet Explicit elevation coordinate included with horizontal coordinates Classified las 1.4 Pilot North B Project Merrick & Co ASPRS ver 1.4 format: 1 = Unclassified 2 = Ground 3 = Automated Low Veg [0.5-5 feet] 4 = Automated Medium Veg [5-20 feet] 5 = Automated High Veg [>20 feet] 6 = Automated Building 7 = Low Noise 9 = Water 17 = Bridge 18 = High Noise 20 = Ignore Ground (breakline proximity) Model key points are bit-flagged and created from ground (class = 2) points using a 5 foot horizontal and a 0.2 foot vertical variance. ASPRS ver 1.4 format: 1 = Unclassified 2 = Ground 3 = Automated Low Veg [0.5-5 feet] 4 = Automated Medium Veg [5-20 feet] 5 = Automated High Veg [>20 feet] 6 = Automated Building 7 = Low Noise 9 = Water 17 = Bridge 18 = High Noise 20 = Ignore Ground (breakline proximity) Model key points are bit-flagged and created from ground (class = 2) points using a 5 foot horizontal and a 0.2 foot vertical variance. 20201228 Doug Jacoby Merrick & Co. Project Manager mailing and physical address

5970 Greenwood Plaza Blvd.

Greenwood Village Co 80111 303-353-3903 doug.jacoby@merrick.com Please refer to the distribution information section. FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998 local time None. None.