In support of U.S. Geological Survey (USGS) Southwest Biological Science Center researchers, and in coordination with the Bureau of Land Management (BLM) and National Ecological Observatory Network (NEON), the USGS National Uncrewed Systems Office (NUSO) conducted uncrewed aircraft systems (UAS) remote sensing flights over two BLM Assessment, Inventory, and Monitoring (AIM) plots at the NEON Moab site in Utah for multi-scale carbon sequestration research on public lands.The UAS data collected include natural color, multispectral, and hyperspectral imagery, and lidar to capture diverse information about vegetation and soils on two dryland sites approximately 40 km south of Moab, Utah. The first site (“site 1”) features intact sagebrush and was mapped on May 3, 2023. The second site (“site 7”) is located on a grazed rangeland environment and was mapped on May 5, 2023. These UAS surveys were conducted in early May 2023 to coincide spatially and temporally with ground-based BLM AIM sampling and airplane-based remote sensing surveys by NEON.
Survey control was established using Propeller AeroPoint temporary ground control points (GCPs) distributed throughout the survey area. GCPs were post-processed with corrections from a concurrently operating Trimble R8s GNSS base station.
Natural color UAS images captured using a Skydio X2D system were processed in photogrammetry software using temporary GCPs to yield structure-from-motion (SfM) point clouds, digital surface models (DSMs), and red, green, blue (RGB) 3-band orthomosaics.
Multispectral UAS images captured using a MicaSense Altum-PT sensor were processed in photogrammetry software using the same temporary GCPs to yield SfM point clouds, DSMs, and 5-band orthomosaics. The 5-band orthomosaics were radiometrically calibrated to units of reflectance in each spectral band (blue, green, red, red edge, and near infrared) spanning the visible and near infrared wavelengths, 475 to 842 nm.
UAS lidar point clouds captured using a YellowScan Vx20-100 scanner (laser wavelength 905 nm) were post-processed kinematic (PPK) corrected to our nearby GNSS base station and each point was assigned RGB values using corresponding natural color orthomosaics at each site.
Hyperspectral UAS images collected using a Headwall Nano-Hyperspec sensor were PPK-corrected and post-processed following the sensor manufacturer’s recommendations to yield ortho-rectified reflectance images with 274 spectral bands spanning the visible and near infrared wavelengths, 398 to 1002 nm.
