Morena N. Hammer Stephen B. DeLong Jessie L. Vermeer Mark A. Bauer Victoria M. Scholl Rezagene A. Milani Tim J. Kuhn Melissa P. Steller Matthew A. Burgess 20250908 1 lidar point cloud data ScienceBase U.S. Geological Survey https://doi.org/10.5066/P13YDQIZ Lidar point clouds (LPCs) were generated from lidar data collected during multiple field campaigns in Central and South Ackerson Meadow, Yosemite National Park, California, November 2023. Small, Uncrewed Aircraft Systems (sUAS) collected lidar data on November 5-6th, 2023, as the first post-restoration collection of the meadow complex. More information regarding the sUAS system used and data collection methods can be found in the Supplemental Information section. LPCs were collected to derive digital terrain models (DTMs) to aid the National Park Service (NPS) in monitoring and assessing the pre- and post-restoration work of Central and South Ackerson Meadow. The lidar data were collected with a YellowScan Mapper Plus lidar scanner, which consists of the Livox Horizon scanner and an Applanix 15 inertial measurement unit. The system was flown on a DJI M600 sUAS with approved government-edition firmware. The lidar data sets were collected on east-west and northeast to southwest oriented transects at 10 meters per second (m/s) at 91 meters (m) above the ground level. The generated LPCs represent data collected at +41/-41 degree scan angles from the nadir, covering a swath of roughly 100 m per transect. The LPCs were RGB (red, green, blue) colorized from imagery collected simultaneously with the lidar using the YellowScan Mapper Plus Camera add-on system. This payload system uses a Sony UMC-R10C camera. Images are directly georeferenced using ray-tracing methods in CloudStation software. Point class attribute information was assigned using TerraScan macro processing. LPCs were z (elevation) translated according to 2019 benchmark control lidar data with LAStools. Point clouds were used to derive digital terrain models (DTMs) with Scripter Golden Software and assessed in ArcGIS Pro. 20231105 20231106 ground condition Complete As needed -119.85518 -119.82050 37.84822 37.82918 None Lidar sUAS YellowScan Mapper Plus DJI M600 Point Cloud Bare Earth Livox Avia Meadow Restoration Wetland UAV mid-elevation meadow Sierra Nevada Range post-restoration pre-restoration meadow restoration erosion USGS Metadata Identifier USGS:681500a2d4be0252ee16650b Places Ackerson Meadow Ackerson Meadow South Yosemite National Park California Sierra Nevada None. Please see 'Distribution Info' for details. None. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations. Morena N. Hammer U.S. Geological Survey Geologist mailing address

1992 Folwell Ave

St. Paul Minnesota 55108 United States NA NA mhammer@usgs.gov U.S. Geological Survey - National Uncrewed Systems Office for the collection of LPCs. Funding was supported by the National Park Service (NPS) and allied partners. File Name: AckersonMeadows_Nov2023_LPC.zip File Size: <13 GB. Operating System: Windows 11. Software utilized: TerraScan ver 025.010, LAStools ver v2.0.3, ArcGIS Pro 3.4.3, Scripter Golden Software ver 5.0.92.488, YellowScan CloudStation , and Trimble Applanix POSPac UAV. During LPC collection, Propeller Aeropoint smart targets were used as checkpoints, placed in known areas with limited (where possible) vegetation. These Aeropoint elevations were corrected using observation data from a Trimble R8s GNSS Base. The smart target data was used to assess the horizontal and vertical accuracy of the lidar point cloud. LPCs were further evaluated by comparing the horizontal and vertical alignment to previously collected lidar data from 2019 (https://rockyweb.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/CA_YosemiteNP_2019_D19/CA_YosemiteNP_2019/). Data falls within expected ranges. The changes in data point density or point omissions are caused by interference of the canopy which stops some points from reaching the ground and returning to the sensor. Data are complete. The Central Ackerson LPC Root Mean Square Error for horizontal accuracy to Aeropoint smart targets was 0.048 meters. The South Ackerson LPC Root Mean Square Error for horizontal accuracy to Aeropoint smart targets was 0.076 meters. The Central Ackerson LPC Root Mean Square Error for vertical accuracy to Aeropoint smart targets was 0.047 meters. The South Ackerson LPC Root Mean Square Error for vertical accuracy to Aeropoint smart targets was 0.050 meters. U.S. Geological Survey 20210528 lidar point cloud data https://rockyweb.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/CA_YosemiteNP_2019_D19/CA_YosemiteNP_2019/ lidar point cloud data 20210528 ground condition USGS LPC's CA_YosemiteNP_2019_D19 Utilized as control data for analyses and alignments. The YellowScan Mapper lidar data were processed and filtered using YellowScan CloudStation software. The recorded Applanix IMU trajectory data were corrected in Trimble Applanix POSPac UAV software. The Trimble R8s basestation observations were corrected using the Online Positioning User Service (OPUS). The resulting PPK-corrected trajectory data file was imported into the CloudStation software to apply the PPK positional corrections to the point cloud. The lever arm offsets and boresight angle corrections were applied to the point cloud, along with a strip adjustment between transect swaths using CloudStation's "robust" strip adjustment setting. Processed data from each field campaign are produced in LASer format (.las) files which were processed into a single .las file per field campaign. More precise information on the setup and deployment of the UAS lidar system used to collect data can be found in the Supplemental Information section. 2023 U.S. Geological Survey, ROCKY MOUNTAIN REGION mailing address

Mail Stop 980, W 6th Ave Kipling St

Lakewood CO 80225 US NA uas@usgs.gov LPCs were converted to LAZ file format (.laz) to optimize storage requirements. LPCs were classified in TerraScan Software (ver 025.010) using macro automation processing steps (see below) and tiled with LAStools (ver v2.0.3) for optimized file access. Classification accuracy was compared to RTK GNSS points and vegetation survey notes. LPCs were used to derive DTMs with Scripter and horizontal and vertical accuracy were compared to flat, stable surfaces from a previous, geoid12b corrected control lidar dataset from 2019 (https://rockyweb.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/CA_YosemiteNP_2019_D19/CA_YosemiteNP_2019/). The Central and South Ackerson Meadow LPCs were z translated by -0.0229 and 0.0158 meters, respectively, using LAStools. Ground, channel cutbank, and vegetation classification macros steps: FnScanClassifyClass("1-22,30-32",2,0) FnScanClassifySurface("2",31,0.150,0,0) FnScanClassifyCloseby("2","0-65535","0-255",32,3,0.150,0,0,1,"31",0,"0-65535",0,"0-255",0) FnScanClassifyClass("2",31,0) FnScanClassifyGround("31",2,"31",1,6.0,99.00,9.00,4.00,0,5.0,0,2.0,0,0,0) FnScanComputeNormals("31",2,0,0,10.000,1) FnScanClassifyNormal("31",13,2,0,-1.000000,1.000000,0,-1.000000,1.000000,1,0.000000,0.300000,1) FnScanClassifyCloseby("31","0-65535","0-255",12,3,0.700,0,0,1,"13",0,"0-65535",0,"0-255",1) FnScanClassifyNormal("12",13,2,0,-1.000000,1.000000,0,-1.000000,1.000000,1,0.000000,0.650000,1) FnScanClassifyClass("13",2,0) FnScanClassifyClass("12",31,0) FnScanClassifyClass("31-32",10,0) FnScanClassifyHgtGrd(2,100.0,10,4,0.700,3.000,0) FnScanClassifyHgtGrd(2,100.0,10,3,0.000,0.700,0) FnScanClassifyHgtGrd(2,100.0,10,5,3.000,900.000,0) Further supervised, fenced classification of thickly vegetated areas: FnScanClassifyHard("2",32,0.020,10.00,1.0,0.01,0.1,1) FnScanClassifyHgtGrd(32,100.0,2,11,0.100,3.000,1) FnScanClassifyHgtGrd(32,100.0,11,3,0.000,0.700,1) FnScanClassifyHgtGrd(32,100.0,11,4,0.700,3.000,1) FnScanClassifyClass("32",2,1) FnScanClassifyClass("11",2,1) USGS LPC's CA_YosemiteNP_2019_D19 2025 Morena N. Hammer U.S. Geological Survey Geologist mailing and physical

1992 Folwell Ave

St. Paul Minnesota 55108 United States NA NA mhammer@usgs.gov Vector Point Universal Transverse Mercator 11 0.9996 -117.0 0.0 500000.0 0.0 coordinate pair 0.04757 0.04757 meters NAD83_NATIONAL_SPATIAL_REFERENCE_SYSTEM_2011 GRS 1980 6378137.0 298.257222101 North American Vertical Datum of 1988 0.01 meters Attribute values Central Ackerson November 2023 LPC LPC generated from sUAS Producer Defined ELEVATION Surface elevation orthometric height NAVD88 (m) using Geoid 12b in NAD83(2011)/UTM Zone 11N. YellowScan CloudStation and LAStools 1403.35 1530.18 m CLASS Each lidar point has a classification value assigned to it according to the ASPRS LAS Specification. YellowScan CloudStation and LAStools 1 (Unclassified) Data have been subjected to a classification algorithm, but the results have emerged in an undefined state. ASPRS LAS Specification 2 (Ground) Data have been subjected to a classification algorithm and identified as bare ground. ASPRS LAS Specification 3 (Low Vegetation) Data have been subjected to a classification algorithm and identified as low vegetation (0-0.7m). ASPRS LAS Specification 4 (Medium Vegetation) Data have been subjected to a classification algorithm and identified as medium vegetation (0.7-3m). ASPRS LAS Specification 5 (High Vegetation) Data have been subjected to a classification algorithm and identified as high vegetation (3-200m). ASPRS LAS Specification 6 (Building) Data have been subjected to a classification algorithm and identified as building. ASPRS LAS Specification 19 (Car) Data have been subjected to a classification algorithm and identified as car. ASPRS LAS Specification INTENSITY Lidar intensity is recorded as the return strength of a laser beam during data collection. YellowScan CloudStation and LAStools 0 65025 RETURN_NUM Return number. Each laser pulse can produce multiple discrete observations as objects in the scene reflect emitted light. YellowScan CloudStation and LAStools 1 First Return Producer defined 2 Second Return Producer defined 3 Third Return Producer defined RETURN_CNT Return count. Total number of returns for the given pulse that produced each point. YellowScan CloudStation and LAStools 1 Single return Producer defined 2 Two returns Producer defined 3 Three returns Producer defined SCAN_ANGLE The scan angle of the laser beam that produced each point where 0 degrees indicates nadir. YellowScan CloudStation and LAStools -42 43 USER_DATA Integer refers to which data set each point originated from. YellowScan CloudStation and LAStools 0 255 SOURCE_ID Integer refers to a unique UAS flight transect. YellowScan CloudStation and LAStools 1001 5012 GPS_TIME Time stamp in GPS seconds at which the light pulse was emitted from the instrument. YellowScan CloudStation and LAStools 81119.328260 162197.687256 RED Red band brightness corresponds to natural color digital number value from the associated image from ray-tracing colorization method. YellowScan CloudStation and LAStools 0 65535 GREEN Green band brightness corresponds to natural color digital number value from the associated image from ray-tracing colorization method. YellowScan CloudStation and LAStools 0 65535 BLUE Blue band brightness corresponds to natural color digital number value from the associated image from ray-tracing colorization method. YellowScan CloudStation and LAStools 0 65535 South Ackerson November 2023 LPC LPC generated from sUAS Producer Defined ELEVATION Surface elevation orthometric height NAVD88 (m) using Geoid 12b in NAD83(2011)/UTM Zone 11N. YellowScan CloudStation and LAStools 1397.87 1493.04 m CLASS Each lidar point has a classification value assigned to it according to the ASPRS LAS Specification. YellowScan CloudStation and LAStools 1 (Unclassified) Data have been subjected to a classification algorithm, but the results have emerged in an undefined state. ASPRS LAS Specification 2 (Ground) Data have been subjected to a classification algorithm and identified as bare ground. ASPRS LAS Specification 3 (Low Vegetation) Data have been subjected to a classification algorithm and identified as low vegetation (0-0.7m). ASPRS LAS Specification 4 (Medium Vegetation) Data have been subjected to a classification algorithm and identified as medium vegetation (0.7-3m). ASPRS LAS Specification 5 (High Vegetation) Data have been subjected to a classification algorithm and identified as high vegetation (3-200m). ASPRS LAS Specification 19 (Car) Data have been subjected to a classification algorithm and identified as a car. ASPRS LAS Specification INTENSITY Lidar intensity is recorded as the return strength of a laser beam during data collection. YellowScan CloudStation and LAStools 0 65025 RETURN_NUM Return number. Each laser pulse can produce multiple discrete observations as objects in the scene reflect light. YellowScan CloudStation and LAStools 1 First Return Producer defined 2 Second Return Producer defined 3 Third Return Producer defined RETURN_CNT Return count. Total number of returns for the given pulse that produced each point. YellowScan CloudStation and LAStools 1 Single return Producer defined 2 Two returns Producer defined 3 Three returns Producer defined SCAN_ANGLE The scan angle of the laser beam that produced each point where 0 degrees indicates nadir. YellowScan CloudStation and LAStools -41 42 USER_DATA Integer refers to which data set each point originated from. YellowScan CloudStation and LAStools 0 255 SOURCE_ID Integer refers to a unique UAS flight transect. YellowScan CloudStation and LAStools 1001 3013 GPS_TIME Time stamp in GPS seconds at which the light pulse was emitted from the instrument. YellowScan CloudStation and LAStools 238331.568976 249568.1931173 RED Red band brightness corresponds to natural color digital number value from the associated image from ray-tracing colorization method. YellowScan CloudStation and LAStools 0 65535 GREEN Green band brightness corresponds to natural color digital number value from the associated image from ray-tracing colorization method. YellowScan CloudStation and LAStools 0 65535 BLUE Blue band brightness corresponds to natural color digital number value from the associated image from ray-tracing colorization method. YellowScan CloudStation and LAStools 0 65535 LPC data files are in .laz format. Hammer, M.N., DeLong, S.B., Vermeer, J.L., Bauer, M.A., Scholl, V.M., Burgess, M.A., Kuhn, T.J., Milani, R.A., and Steller, M.P., 2025. Lidar point clouds, rasters, and RTK GNSS survey data for pre- and post-restoration of Ackerson Meadows, Yosemite National Park, California, USA. U.S. Geological Survey data release. https://doi.org/10.5066/P13YDQIZ Morena N. Hammer U.S. Geological Survey Geologist mailing and physical

1992 Folwell Ave

St. Paul Minnesota 55108 United States NA NA mhammer@usgs.gov This database has been approved for release by the U.S. Geological Survey (USGS). Although this database has been subjected to rigorous review and is substantially complete, the USGS reserves the right to revise the data pursuant to further analysis and review. Furthermore, it is released on condition that neither the USGS nor the U.S. Government may be held liable for any damages resulting from its authorized or unauthorized use. Although these data have been processed successfully on a computer System at the USGS, no warranty, expressed or implied is made regarding the display or utility of the data for other purposes, nor on any other system, nor shall the act of distribution constitute any such warranty. The USGS or the U.S. Government shall not be held liable for improper or incorrect use of the data described and/or contained herein. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Digital Data https://doi.org/10.5066/P13YDQIZ None 20260319 Morena N. Hammer U.S. Geological Survey Geologist mailing address

1992 Folwell Ave

St. Paul Minnesota 55108 US NA NA mhammer@usgs.gov FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998