This portion of the data release presents a topographic point cloud of the debris flow at South Fork Campground in Sequoia National Park. The point cloud was derived from structure-from-motion (SfM) photogrammetry using aerial imagery acquired during an uncrewed aerial systems (UAS) survey on 30 April 2024, conducted under authorization from the National Park Service. The raw imagery was acquired with a Ricoh GR II digital camera featuring a global shutter. The UAS was flown on pre-programmed autonomous flight lines spaced to provide approximately 70 percent overlap between images from adjacent lines, from an approximate altitude of 110 meters above ground level (AGL), resulting in a nominal ground-sample-distance (GSD) of 2.9 centimeters per pixel. The imagery was geotagged using positions from the UAS onboard single-frequency autonomous GPS. Survey control was established using temporary ground control points (GCPs) consisting of a combination of small square tarps with black-and-white cross patterns and temporary chalk marks placed on the ground. The GCP positions were measured using dual-frequency real-time kinematic (RTK) GPS with corrections referenced to a static base station operating nearby. The images and GCP positions were used for structure-from-motion (SfM) photogrammetric processing to create a topographic point cloud, a high-resolution orthomosaic image, and a DSM. The point cloud contains 284,906,970 points with an average point-spacing of one point every three centimeters. The point cloud has not been classified, however points with confidence less than three (a measure of the number of depth maps used to generate a point) have been assigned a classification value of 7, which represents low noise. The point cloud is provided in a cloud optimized LAZ format to facilitate cloud-based queries and display.

This portion of the data release presents aerial images of the debris flow at South Fork Campground in Sequoia National Park. The images were acquired during an uncrewed aerial systems (UAS) survey on 30 April 2024, conducted under authorization from the National Park Service. The imagery was acquired with a Ricoh GR II digital camera featuring a global shutter. The camera was mounted to the UAS using a fixed mount, in an approximately nadir orientation. The camera was set to acquire images at 1 hertz, using an external intervalometer. The UAS was flown on pre-programmed autonomous flight lines spaced to provide approximately 70 percent overlap between images from adjacent lines, from an approximate altitude of 110 meters above ground level (AGL), resulting in a nominal ground-sample-distance (GSD) of 2.9 centimeters per pixel. The images were geotagged using positions from the UAS onboard single-frequency autonomous GPS. The original images were acquired in Adobe DNG format but have been converted to JPG format to reduce their size and to facilitate distribution. During the conversion, adjustments were made to the exposure value (EV), to improve image brightness. Only the images which were used for the creation of the topographic data products (also presented in this data release) have been included. Images of the takeoff and landing sequence, as well as images from outside the area of interest have been omitted.

This portion of the data release presents aerial images of the debris flow at South Fork Campground in Sequoia National Park. The images were acquired during an uncrewed aerial systems (UAS) survey on 30 April 2024, conducted under authorization from the National Park Service. The imagery was acquired with a Ricoh GR II digital camera featuring a global shutter. The camera was mounted to the UAS using a fixed mount, in an approximately nadir orientation. The camera was set to acquire images at 1 hertz, using an external intervalometer. The UAS was flown on pre-programmed autonomous flight lines spaced to provide approximately 70 percent overlap between images from adjacent lines, from an approximate altitude of 110 meters above ground level (AGL), resulting in a nominal ground-sample-distance (GSD) of 2.9 centimeters per pixel. The images were geotagged using positions from the UAS onboard single-frequency autonomous GPS. The original images were acquired in Adobe DNG format but have been converted to JPG format to reduce their size and to facilitate distribution. During the conversion, adjustments were made to the exposure value (EV), to improve image brightness. Only the images which were used for the creation of the topographic data products (also presented in this data release) have been included. Images of the takeoff and landing sequence, as well as images from outside the area of interest have been omitted.

This portion of the data release presents a high-resolution Digital Surface Models (DSM) of the debris flow at South Fork Campground in Sequoia National Park. The DSM has a resolution of 10 centimeters per pixel and was derived from structure-from-motion (SfM) photogrammetry using aerial imagery acquired during an uncrewed aerial systems (UAS) survey on 30 April 2024, conducted under authorization from the National Park Service. The raw imagery was acquired with a Ricoh GR II digital camera featuring a global shutter. The UAS was flown on pre-programmed autonomous flight lines spaced to provide approximately 70 percent overlap between images from adjacent lines, from an approximate altitude of 110 meters above ground level (AGL), resulting in a nominal ground-sample-distance (GSD) of 2.9 centimeters per pixel. The raw imagery was geotagged using positions from the UAS onboard single-frequency autonomous GPS. Survey control was established using temporary ground control points (GCPs) consisting of a combination of small square tarps with black-and-white cross patterns and temporary chalk marks placed on the ground. The GCP positions were measured using dual-frequency real-time kinematic (RTK) GPS with corrections referenced to a static base station operating nearby. The images and GCP positions were used for structure-from-motion (SfM) photogrammetric processing to create a topographic point cloud, a high-resolution orthomosaic image, and a DSM. The DSM is provided in a cloud optimized GeoTIFF format with internal overviews and masks to facilitate cloud-based queries and display.

This portion of the data release presents a high-resolution Digital Surface Models (DSM) of the debris flow at South Fork Campground in Sequoia National Park. The DSM has a resolution of 10 centimeters per pixel and was derived from structure-from-motion (SfM) photogrammetry using aerial imagery acquired during an uncrewed aerial systems (UAS) survey on 30 April 2024, conducted under authorization from the National Park Service. The raw imagery was acquired with a Ricoh GR II digital camera featuring a global shutter. The UAS was flown on pre-programmed autonomous flight lines spaced to provide approximately 70 percent overlap between images from adjacent lines, from an approximate altitude of 110 meters above ground level (AGL), resulting in a nominal ground-sample-distance (GSD) of 2.9 centimeters per pixel. The raw imagery was geotagged using positions from the UAS onboard single-frequency autonomous GPS. Survey control was established using temporary ground control points (GCPs) consisting of a combination of small square tarps with black-and-white cross patterns and temporary chalk marks placed on the ground. The GCP positions were measured using dual-frequency real-time kinematic (RTK) GPS with corrections referenced to a static base station operating nearby. The images and GCP positions were used for structure-from-motion (SfM) photogrammetric processing to create a topographic point cloud, a high-resolution orthomosaic image, and a DSM. The DSM is provided in a cloud optimized GeoTIFF format with internal overviews and masks to facilitate cloud-based queries and display.

This portion of the data release presents aerial video acquired during the uncrewed aerial systems (UAS) survey of the debris flow at South Fork Campground in Sequoia National Park, conducted under authorization from the National Park Service. The video shows low-altitude oblique and nadir perspectives of the lower 1.3 kilometers of the debris flow. The video is being included as part of the data release to provide additional context for the geohazards assessment of the area.

This portion of the data release presents aerial video acquired during the uncrewed aerial systems (UAS) survey of the debris flow at South Fork Campground in Sequoia National Park, conducted under authorization from the National Park Service. The video shows low-altitude oblique and nadir perspectives of the lower 1.3 kilometers of the debris flow. The video is being included as part of the data release to provide additional context for the geohazards assessment of the area.

This portion of the data release presents a high-resolution orthomosaic image of the debris flow at South Fork Campground in Sequoia National Park. The orthomosaic has a resolution of 3 centimeters per pixel and was derived from structure-from-motion (SfM) photogrammetry using aerial imagery acquired during an uncrewed aerial systems (UAS) survey on 30 April 2024, conducted under authorization from the National Park Service. The raw imagery was acquired with a Ricoh GR II digital camera featuring a global shutter. The UAS was flown on pre-programmed autonomous flight lines spaced to provide approximately 70 percent overlap between images from adjacent lines, from an approximate altitude of 110 meters above ground level (AGL), resulting in a nominal ground-sample-distance (GSD) of 2.9 centimeters per pixel. The raw imagery was geotagged using positions from the UAS onboard single-frequency autonomous GPS. Survey control was established using temporary ground control points (GCPs) consisting of a combination of small square tarps with black-and-white cross patterns and temporary chalk marks placed on the ground. The GCP positions were measured using dual-frequency real-time kinematic (RTK) GPS with corrections referenced to a static base station operating nearby. The images and GCP positions were used for structure-from-motion (SfM) photogrammetric processing to create a topographic point cloud, a high-resolution orthomosaic image, and a Digital Surface Model (DSM). The orthomosaic image is provided in a cloud optimized GeoTIFF format with internal overviews and masks to facilitate cloud-based queries and display.

This portion of the data release presents a high-resolution orthomosaic image of the debris flow at South Fork Campground in Sequoia National Park. The orthomosaic has a resolution of 3 centimeters per pixel and was derived from structure-from-motion (SfM) photogrammetry using aerial imagery acquired during an uncrewed aerial systems (UAS) survey on 30 April 2024, conducted under authorization from the National Park Service. The raw imagery was acquired with a Ricoh GR II digital camera featuring a global shutter. The UAS was flown on pre-programmed autonomous flight lines spaced to provide approximately 70 percent overlap between images from adjacent lines, from an approximate altitude of 110 meters above ground level (AGL), resulting in a nominal ground-sample-distance (GSD) of 2.9 centimeters per pixel. The raw imagery was geotagged using positions from the UAS onboard single-frequency autonomous GPS. Survey control was established using temporary ground control points (GCPs) consisting of a combination of small square tarps with black-and-white cross patterns and temporary chalk marks placed on the ground. The GCP positions were measured using dual-frequency real-time kinematic (RTK) GPS with corrections referenced to a static base station operating nearby. The images and GCP positions were used for structure-from-motion (SfM) photogrammetric processing to create a topographic point cloud, a high-resolution orthomosaic image, and a Digital Surface Model (DSM). The orthomosaic image is provided in a cloud optimized GeoTIFF format with internal overviews and masks to facilitate cloud-based queries and display.

This portion of the data release presents topographic Global Navigation Satellite System (GNSS) measurements acquired during the UAS survey of the debris flow at South Fork Campground in Sequoia National Park. The data contain the locations of the temporary ground control points (GCPs) used for the structure-from-motion (SfM) processing, as well as topographic measurements collected using a backpack-mounted GNSS rover. For the GCPs, 23 temporary points consisting of a combination of small square tarps with black-and-white cross patterns and "X" marks placed on the ground using temporary chalk were distributed throughout the survey area. For each GCP measurement the GPS receiver was placed on a fixed-height tripod and set to occupy the GCP for a minimum occupation time of one minute. For the topographic data acquisition, a GNSS rover was mounted to a backpack and used to collect continuous 1-second data on bare-ground surfaces of the debris flow site that were accessible on foot. The GNSS measurements were made using a real-time kinematic (RTK) GPS, with corrections from a GPS base station located on a temporary benchmark ("SFKW") established on the foot of the debris flow. The approximate base station position was initially derived using an autonomous position. The final coordinates for SFKW were derived using a seven-hour static occupation, submitted to the National Geodetic Survey Online User Positioning Service (OPUS-S). The resulting OPUS solution conforms to the quality standards for a USGS Level II single-base survey. After the survey was completed, the RTK data were adjusted using the final SFKW position using the Trimble Business Center software package. The GNSS data are presented in a comma-delimited text file.