Merrick & Company 20230426 las data LIDAR-derived binary (.las) files containing classified points of all returns. We have eighteen (18) classifications: Unclassified, Ground, Low Veg (0.5-5ft), Medium Veg (5-20ft), High Veg (>20ft), Building, Low Noise, Water, Rail, Road Surface, Wire-Guard (Shield), Wire-Conductor (Phase), Transmission Tower, Wire-Structure Connector, Bridge Decks, High Noise, Overhead Structure and Ignore Ground. Unless otherwise stated, the lidar mapping requirements and deliverables will meet the Quality Level One (QL1) standards as outlined in the USGS NGP Lidar Base Specification 2021, Revision A. The increased lidar density requirement for this project will be met by achieving an Aggregate Nominal Point Density (ANPD) of greater than or equal to 20 points per square meter (>20ppsm), or less than or equal to twenty-two centimeters (<0.22m) Aggregate Nominal Point Spacing (ANPS). Tile sizes are 2500ft x 2500ft. This task is for providing a spring 2022 leaf-off and snow-free high-density lidar survey over an Area of Interest (AOI) of approximately 1,199 square miles covering Cook County, Illinois (and its surrounds). Derivative products include Digital Terrain Model (DTM), Digital Surface Model (DSM), and one-foot contours. Lidar data captured through this project will be the basis for the creation, update and capture of other separately remotely sensed planimetric data including updates to roads, 3D buildings and footprints, tree inventory, hydrographic features and to provide an accurate Digital Terrain Model (DTM) for annually captured orthoimagery. The County intends to use this data for change detection from previous mission data for assessment purposes and to ensure adherence to building code enforcement. Its uses also include, ecology management, engineering, urban planning and transportation studies, watershed delineation and to provide improved flood and disaster modeling and mitigation efforts. USGS-NGP Lidar Base Specification 2021 rev. A. Optech Galaxy Prime Airborne Laser Terrain Mappers (ALTM) 5060420 & 5060428(G2 Mount) 8 0.224 20 0.224 20 2259 170 57 69 1200 3.5 1.1295 1064 1 0.25 2433 55.5 National Geodetic Survey (NGS) Geoid18 0.175 0.0 0 1.4 6 Withheld (ignore) points were identified in these files using the standard LAS withheld bit. Swath "overage" points were not identified in these files using the standard LAS overlap bit. 12 1 Unclassified 2 Ground 3 Low Veg 4 Medium Veg 6 High Veg 7 Low Noise 9 Water 10 Rail 11 Road Surface 13 Wire - Guard (Shield) 14 Wire - Conductor (Phase) 15 Transmission Tower 16 Wire-Structure Connector 17 Bridge Deck 18 High Noise 19 Overhead Structure 20 Ignore Breakline 20220405 20220629 ground condition Complete Unknown -88.293792697899 -87.4974076898388 42.1780983106989 41.441394670546 995000 1212500 2007500 1740000 None Breaklines Elevation Data Lidar DSM Intensity None Cook County, Illinois No restrictions apply to these data. None. 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. Vertical (absolute) accuracy of the lidar data will meet AccuracyZ = 0.6ft (18.2cm) at 95% confidence (RMSEZ = 0.3ft [9.25cm]) in accordance with the National Standard for Spatial Data Accuracy (FGDC-STD-007.3-1998) when tested against an independent source of higher accuracy using a minimum of twenty (20) checkpoints that fall within well-defined open terrain. Lidar data was collected using Optech Galaxy Prime 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, low veg, medium veg, high veg, building, low noise, low noise, water, rail, road surface, wire-guard, wire-conductor, transmission tower, wire-structure connector, bridge decks, high noise, overhead structure and ignore ground. The data was next taken into MARS to reclassify the erroneous points that may remain in the lidar point cloud after auto filter. Twenty points per square meter. 20230426 Doug Jacoby Merrick & Company Project Manager mailing and physical address

5970 Greenwood Plaza Blvd.

Greenwood Village CO 80111 303-353-3903 doug.jacoby@merrick.com LiDAR swath data was measured to have an average of 0.224 meter nominal pulse spacing and 20.0 pulses per meter. The method used was counting first return points within each swath, then dividing by the area of the extent of the corresponding swath to get density. NPS was mathematically derived from this density number. This was performed on each swath then averaged to generate the two numbers above. This USGS method does not consider swath sidelap in these calculations. 20230426 Doug Jacoby Merrick & Company Project Manager mailing and physical address

5970 Greenwood Plaza Blvd.

Greenwood Village CO 80111 303-353-3903 doug.jacoby@merrick.com Point NAD 1983 2011 StatePlane Illinois East FIPS 1201 Ft US 0.999975 -88.33333333333333 36.66666666666666 984250.0 0.0 coordinate pair 0.000000007286249381621703 0.000000007286249381621703 foot_us D NAD 1983 2011 GRS 1980 6378137.0 298.257222101 North American Vertical Datum of 1988 Geoid2018 0.001 feet Explicit elevation coordinate included with horizontal coordinates 20230426 Merrick-Surdex Joint Venture, LLP mailing and physical address

5970 Greenwood Plaza Blvd

Greenwood Village CO 80111 USA 303-353-3903 FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998 IL_Cook_DSM_2022