Sanborn Map Company, Inc. 20200727 Lidar point cloud Product: These lidar data are processed Classified LASv1.4 files, formatted to 794 individual 2,500 ft x 2,500 ft tiles clipped to the BPA; used to create 794 individual 2,500 ft x 2,500 ft tiled intensity imagery, tiled bare-earth DEMs, and contours. Geographic Extent: Brazos County, TX, covering the approximately 155 square miles. Dataset Description:The College_Station_TX_Lidar project called for the planning, acquisition, processing and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.35 meters (QL1). 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, U.S. Survey Feet and vertical datum of NAVD88 (GEOID12B), Feet. Lidar data was delivered as processed Classified LASv1.4 files, formatted to 794 individual 2,500 ft x 2,500 ft tiles clipped to the BPA, and as 794 individual 2,500 ft x 2,500 ft tiled intensity imagery, tiled bare-earth DEMs, and contours. Ground Conditions: Lidar was collected in early 2020, 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, The Sanborn Map Company, Inc. established a total of 7 ground control points that were used to calibrate the lidar to known ground locations established throughout the project area. An additional 25 independent accuracy check points, 20 in Open Terrain/Bare-Earth and Urban landcovers (20 NVA points), 5 in Grass, Brush and Trees categories (5 VVA points), were used to assess the vertical accuracy of the data. These check points were not used to calibrate or post process the data. To acquire detailed surface elevation data for use in conservation planning, design, research, floodplain mapping, dam safety assessments and elevation modeling, etc. Classified LAS files are used to show the manually reviewed bare-earth surface. This allows the user to create Intensity Images, Breaklines and Raster DEM. The purpose of these lidar data was to produce high accuracy 3D hydro-flattened Digital Elevation Model (DEM) with a 1 foot cell size. These raw lidar point cloud data were used to create classified lidar LAS files, intensity images, 3D breaklines, hydro-flattened DEMs, and contours necessary. Contractor: The Sanborn Map Company, Inc. Lidar data were acquired by Sanborn. All follow-on processing was completed by the prime contractor. USGS Lidar Base Specification v1.3 Leica TerrainMapper 15 0.35 8.27 0.35 8.27 2197 160 40 150.0 1710.0 4 0.52 1064 15 0.25 1599 20 National Geodetic Survey (NGS) Geoid12B 0.500 0.249 20 0.248 20 0.275 5 1.4 6 Withheld "ignored" 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 Unclassified 2 Bare Earth Ground 7 Low Noise 9 Water 17 Bridge Decks 18 High Noise 20 Ignored Ground 20200225 20200227 ground condition Complete None planned -96.4234904459 -96.1359033831 30.6584128237 30.4440751502 None Model LAS Point Cloud Remote Sensing Elevation Data Lidar None Texas Brazos No restrictions apply to these data. None. 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. 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. The project specifications require the accuracy (ACCz) of the lidar point cloud be calculated and reported in two ways: 1. The required NVA is: 19.6 cm at a 95% confidence level, derived according to NSSDA, i.e., based on RMSE of 10 cm in the "bare earth" and "urban" land cover classes. This is a required accuracy. The NVA was tested with 20 check points located in bare earth and urban (non-vegetated) areas. 2. Vegetated Vertical Accuracy (VVA): VVA shall be reported for "brushlands/low trees" and "tall weeds/crops" land cover classes. The target VVA is: 30 cm at the 95th percentile, derived according to ASPRS Guidelines, Vertical Accuracy Reporting for Lidar Data, i.e., based on the 95th percentile error in all vegetated land cover classes combined. This is a target accuracy. The VVA was tested with 5 check points located in tall weeds/crops and brushlands/low trees (vegetated) areas. The check points were distributed throughout the project area and were surveyed using GPS techniques. See survey report for additional survey methodologies. AccuracyZ has been tested to meet 19.6 cm or better Non-Vegetated Vertical Accuracy at 95% confidence level using RMSE(z) x 1.9600 as defined by the National Standards for Spatial Data Accuracy (NSSDA); assessed and reported using National Digital Elevation Program (NDEP)/ASRPS Guidelines. 0.248 Tested 0.248 feet NVA at a 95% confidence level using RMSE(z) x 1.9600 as defined by the National Standards for Spatial Data Accuracy (NSSDA). The NVA of the lidar was calculated using 20 independent check points located in the Bare Earth and Urban land cover categories. 0.275 Tested 0.275 feet VVA at the 95th percentile was calculated using 5 check points located in the Brushlands and Low Trees and Tall Weeds and Crops land cover categories, derived according to ASPRS Guidelines, Vertical Accuracy Reporting for Lidar Data. Tested against the lidar. The Sanborn Map Company, Inc. 2020 vector digital data and tabular digital data Colorado Springs, CO The Sanborn Map Company, Inc. None 50 Email 2020 ground condition 312020312_CollegeStationTX_Lidar_Survey This data source was used (along with airborne GNSS/IMU data) to georeference the lidar point cloud data. The following steps describe the Raw Data Processing and Calibration process: 1) Technicians processed the raw data to LAS format flight lines using the ABGNSS/IMU solution. 2) Technicians use TerraSolid TerraMatch to calculate initial calibration adjustment angles by mission and/or block. This is accomplished by identifying ground and above ground feature observations between flight-lines and calculating the offsets. The technician then analyzed the results and made any necessary additional adjustment until it is acceptable. 3) Once the angle calculation was completed the adjusted settings were applied to all of the flight-lines of the mission and/or block and checked for consistency. The technicians utilized commercial and proprietary software packages to analyze how well flight-line overlaps match and adjusted as necessary until the results met the project specifications. 4) 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 RMSDz or within swath overlap (between adjacent swaths). 5) The technicians ran a final vertical accuracy check of the calibrated point cloud 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 1.3, and breaklines were collected for water features. Bare earth DEMs were exported from the classified point cloud using collected breaklines for hydroflattening. 312020312_CollegeStationTX_Lidar_Survey 2020 The Sanborn Map Company, Inc. mailing and physical

1935 Jamboree Drive

Suite 100

Colorado Springs CO 80920 USA (866)726-2676 sanborn.com Monday - Friday 8 a.m. to 5 p.m. (Mountain Time) If unable to reach the contact by telephone, please send an email. You should get a response within 24 hours. LAS Point Classification: The point classification is performed as described below. The bare-earth surface is manually reviewed to ensure correct classification on the Class 2 (Ground) points. After the bare-earth surface is edited and QC'd, it is then used to generate all hydro-breaklines through heads-up digitization. All ground (ASPRS Class 2) lidar data inside of the Lake Pond and River Pond hydro flattening breaklines were then classified to water (ASPRS Class 9) using LP360 functionality. A buffer of 0.35 m was also used around each hydro-flattened feature to classify these ground (ASPRS Class 2) points to Ignored ground (ASPRS Class 20). All Lake Pond Island and River Stream Island features were checked to ensure that the ground (ASPRS Class 2) points were reclassified to the correct classification after the automated classification was completed. All overlap data was processed through automated functionality provided by TerraScan to classify the overlapping flight-line data to approved classes by USGS. The overlap data was classified using standard LAS overlap bit. These classes were created through automated processes only and were not verified for classification accuracy. All data was manually reviewed and any remaining artifacts removed using functionality provided by TerraScan and TerraModeler. Global Mapper is used as a final check of the bare-earth dataset. GeoCue was then used to create the deliverable industry-standard LAS files for the Classified Point Cloud Data. LAStools, LP360 and TerraScan software was used to perform statistical analysis of the classes in the LAS files, on a per tile level to verify classification metrics and full LAS header information. 20200727 Point NAD 1983 2011 StatePlane Texas Central FIPS 4203 Ft US 31.88333333333333 30.11666666666667 -100.3333333333333 29.66666666666667 2296583.333 9842500.000000002 coordinate pair 0.001 0.001 foot D NAD 1983 2011 GRS 1980 6378137.0 298.257222101 North American Vertical Datum of 1988 0.001 foot Explicit elevation coordinate included with horizontal coordinates 20200727 The Sanborn Map Company, Inc. mailing and physical

1935 Jamboree Drive

Suite 100

Colorado Springs CO 80920 USA (866)726-2676 FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998