Dewberry 20190110 Lidar point cloud Product: These lidar data are processed Classified LAS 1.4 files, formatted to 4398 individual 1500 m x 1500 m tiles; used to create intensity images, 3D breaklines and hydro-flattened DEMs as necessary. Geographic Extent: Texas West Central Block 04, covering approximately 3705 square miles. Dataset Description: Texas West Central Block 04 2018 Lidar project called for the Planning, Acquisition, processing and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.7 meter. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification, Version 1.2. The data was developed based on a horizontal projection/datum of NAD83 (2011), Universal Transverse Mercator, meters and vertical datum of NAVD88 (GEOID12B), meters. Lidar data was delivered as processed Classified LAS 1.4 files, formatted to 4398 individual 1500 m x 1500 m tiles, as tiled Intensity Imagery, and as tiled bare earth DEMs; all tiled to the same 1500 m x 1500 m schema. Ground Conditions: Lidar was collected in February and March 2018, 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, Dewberry established a total of 33 ground control points that were used to calibrate the lidar to known ground locations established throughout the Texas West Central Block 04 project area. An additional 95 independent accuracy checkpoints, 57 in Bare Earth and Urban landcovers (57 NVA points), 38 in Tall Grass and Brushland/Low Trees categories (38 VVA points), were used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data. U.S. Geological Survey (USGS) - National Geospatial Program (NGP) Lidar Base Specification v1.2 Riegl VQ-Q1560i 15 0.7 2 0.7 2 5700 147 58 201 1000 3 0.43 1064 1 0.25 1947 15 National Geodetic Survey (NGS) GEOID12B 0.738 0.077 57 0.072 57 0.076 38 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 7 Low Noise 9 Water 10 Ignored Ground 17 Bridge Decks 18 High Noise 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 meter cell size. These lidar point cloud data were used to create intensity images, 3D breaklines, and hydro-flattened DEMs as necessary. USGS Contract No. G16PC00020 CONTRACTOR: Dewberry SUBCONTRACTOR: Axis Geospatial Lidar data were acquired and calibrated by Airborne Imaging. All follow-on processing was completed by the prime contractor. 20180210 20180308 ground condition Complete None planned -102.898414 -101.924179 32.519237 31.053743 700500 789000 3600000 3439533 None Model LAS Point Cloud Remote Sensing Elevation Data Lidar None Texas New Mexico Oklahoma Southeastern New Mexico West Texas 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 that only Non-Vegetated Vertical Accuracy (NVA) be computed for raw lidar point cloud swath files. The required accuracy (ACCz) 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. The NVA was tested with 57 checkpoints located in bare earth and urban (non-vegetated) areas. These check points were not used in the calibration or post processing of the lidar point cloud data. The checkpoints were distributed throughout the project area and were surveyed using GPS techniques. See survey report for additional survey methodologies. Elevations from the unclassified lidar surface were measured for the x,y location of each check point. Elevations interpolated from the lidar surface were then compared to the elevation values of the surveyed control points. 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. 0.077 Tested 0.077 meters 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 raw lidar point cloud swath files was calculated against TINs derived from the final calibrated and controlled swath data using 57 independent checkpoints located in Bare Earth and Urban land cover classes. Dewberry Consultants LLC 20180531 vector digital data and tabular digital data Lanham, Maryland Dewberry Consultants, LLC, Survey department None N/A/ 1640 Online 20180312 ground condition Texas_West_Central_Ground_Control_Points This data source was used (along with airborne GPS/IMU data) to georeference the lidar point cloud data. 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 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 1.2, and breaklines were collected for water features. Bare earth DEMs were exported from the classified point cloud using collected breaklines for hydroflattening. Texas_West_Central_Ground_Control_Points 20180312 Axis Geospatial, LLC Justin Lahman mailing and physical

28640 Marys Court STE 200

Easton MD 21601 USA (410) 822-1441 jlahman@axisgeospatial.com Monday - Friday 8 a.m. to 4 p.m. (Central 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 then manually reviewed to ensure correct classification on the Class 2 (Ground) points. After the bare-earth surface is finalized, 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 Double Line Drain hydro flattening breaklines were then classified to water (ASPRS Class 9) using TerraScan macro functionality. A buffer of 0.7 meters was also used around each hydro-flattened feature to classify these ground (ASPRS Class 2) points to Ignored ground (ASPRS Class 10). All Lake Pond Island and Double Line Drain 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. Due to software limitations within TerraScan, these classes were used to trip the withheld bit within various software packages. These processes were reviewed and accepted by USGS through numerous conference calls and pilot study areas. All data was manually reviewed and any remaining artifacts removed using functionality provided by TerraScan and TerraModeler. Global Mapper us used as a final check of the bare earth dataset. GeoCue was then used to create the deliverable industry-standard LAS files for both the All Point Cloud Data and the Bare Earth. Dewberry proprietary software was used to perform final statistical analysis of the classes in the LAS files, on a per tile level to verify final classification metrics and full LAS header information. 20180515 Point Universal Transverse Mercator 13 0.9996 -105.000000 0.0 500000 0.0 coordinate pair 0.01 0.01 meters North American Datum of 1983 (2011) Geodetic Reference System 80 6378137 298.257222101 North American Vertical Datum of 1988 0.01 meters Explicit elevation coordinate included with horizontal coordinates 20181115 Dewberry mailing and physical

1000 N Ashley Drive, suite 801

Tampa FL 33602 USA (813)225-1325 FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998