Matt Nolan Ann Gibbs Alexander G. Snyder 20221115 1.0 raster digital data (GeoTIFF) data release DOI:10.5066/P9PGJNE9 Pacific Coastal and Marine Science Center, Santa Cruz, California U.S. Geological Survey https://doi.org/10.5066/P9PGJNE9 https://www.sciencebase.gov/catalog/item/62854aebd34e3bef0c9a6b3b Matt Nolan Ann E. Gibbs Alexander G. Snyder 2022 1.0 raster and vector digital files data release DOI:10.5066/P9PGJNE9 Pacific Coastal and Marine Science Center, Santa Cruz, CA U.S. Geological Survey suggested citation: Nolan, M., Gibbs, A.E., and Snyder, A.G., 2022, Alaska coastal orthoimagery and elevation data: Icy Cape to Cape Prince of Wales, 2016: U.S. Geological Survey data release, https://doi.org/10.5066/P9PGJNE9. https://doi.org/10.5066/P9PGJNE9 This part of the data release presents digital elevation models (DEMs) spanning the ocean shoreline of Alaska from Kivalina to Cape Espenberg. Aerial images were collected, and data were processed, by Fairbanks Fodar (https://www.fairbanksfodar.com) in Fairbanks, Alaska, for the U.S. Geological Survey. The aerial images, from which the DEMs were created, were collected in 2016 between August 29 and September 4 and extend from the shoreline to 400-4000 meters inland. The aerial images were collected with precise Global Positioning System (GPS) navigation data from a manned aircraft and were then processed into DEMs photogrammetrically using structure-from-motion (SFM) processing methods as described in Nolan and others, 2015. The included files contain single-band, 32-bit, floating point raster data and are available in GeoTIFF format with 20 cm cell size. The DEM rasters were converted to cloud optimized GeoTIFF format by USGS researchers. Due to file size and number limitations, the DEMs have been divided into three groups by geographic location. Users are encouraged to use the Tile Index shapefile, which is also available in this data release, to identify elevation data files that are appropriate to a specific area of interest. Fairbanks Fodar was contracted by the USGS to acquire new airborne data to process into orthoimagery, digital elevation models, and elevation point clouds. USGS researchers use the digital elevation models to characterize coastal geomorphology. The Tile Index shapefile, also available in this data release, provides an outline of the data in each orthoimagery and elevation data file as well as the name of the file. Once the appropriate filenames are identified, users can either download files to their local server or stream the Cloud Optimized GeoTIFF (COG) directly to any COG supporting GIS. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, as well as in Esri format, this metadata file may include some Esri-specific terminology. 20160829 20160904 ground condition at time data were collected Complete None planned -165.2333 -160.7201 67.9779 65.9911 ISO 19115 Topic Category oceans elevation ImageryBaseMapsEarthCover Data Categories for Marine Planning Physical habitats and geomorphology Bathymetry and elevation USGS Thesaurus structure from motion coastal processes geospatial datasets remote sensing aerial photography image collections geomorphology earth sciences geography coastal processes digital elevation models Marine Realms Information Bank (MRIB) keywords coast beach cliff beach ridge shore None U.S. Geological Survey USGS Coastal and Marine Hazards and Resources Program CMHRP Pacific Coastal and Marine Science Center PCMSC USGS Metadata Identifier USGS:62854aebd34e3bef0c9a6b3b Geographic Names Information System (GNIS) State of Alaska Cape Krusenstern Kotzebue Sound Kotzebue Deering Cape Espenberg No access constraints USGS-authored or produced data and information are in the public domain from the U.S. Government and are freely redistributable with proper metadata and source attribution. Please recognize and acknowledge the U.S. Geological Survey and Fairbanks Fodar as the originator(s) of the dataset and in products derived from these data. U.S. Geological Survey, Pacific Coastal and Marine Science Center PCMSC Science Data Coordinator mailing and physical

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Santa Cruz CA 95060 831-427-4747 pcmsc_data@usgs.gov https://www.sciencebase.gov/catalog/file/get/62854aebd34e3bef0c9a6b3b?name=DEM_Example.jpg&allowOpen=true Graphic depicts an example of the elevation digital elevation model data available in this release. JPEG Data collection was funded by the U.S. Geological Survey. Data acquisition and processing were conducted by Fairbanks Fodar. Microsoft Windows 10, Agisoft Photoscan, ArcMap 10.6, gdal v3.3.1 M. Nolan C. Larsen M. Sturm 2015 Nolan, M., Larsen, C., and Sturm, M., 2015, Mapping snow depth from manned aircraft on landscape scales at centimeter resolution using structure-from-motion photogrammetry: The Cryosphere, v. 9, p. 1445–1463, https://doi.org/10.5194/tc-9-1445-2015. https://doi.org/10.5194/tc-9-1445-2015 Alexander G. Snyder Ann E. Gibbs 2019 Snyder, A.G., and Gibbs, A.E., 2019, National assessment of shoreline change: A GIS compilation of updated vector shorelines and associated shoreline change data for the north coast of Alaska, Icy Cape to Cape Prince of Wales: U.S. Geological Survey data release, https://doi.org/10.5066/P9H1S1PV. https://doi.org/10.5066/P9H1S1PV Ann E. Gibbs Alexander G. Snyder Bruce M. Richmond 2019 Gibbs, A.E., Snyder, A.G., and Richmond, B.M., 2019, National assessment of shoreline change—Historical shoreline change along the north coast of Alaska, Icy Cape to Cape Prince of Wales: U.S. Geological Survey Open-File Report 2019–1146, 52 p., https://doi.org/10.3133/ofr20191146. https://doi.org/10.3133/ofr20191146 Jacquelyn R. Overbeck Richard M. Buzard Mark M. Turner Katie Y. Miller Roberta J.T. Glenn 2020 Overbeck, J.R., Buzard, R.M., Turner, M.M., Miller, K.Y., and Glenn, R.J., 2020, Shoreline change at Alaska coastal communities: Alaska Division of Geological & Geophysical Surveys Report of Investigation 2020-10, 29 p., 47 sheets, https://doi.org/10.14509/30552. https://doi.org/10.14509/30552 Quantum Spatial, Incorporated (QSI) 2019 A formal evaluation performed by Quantum Spatial, Incorporated (QSI; 2019) compared these data to vertical control points and other data sources(see the Attribute Accuracy Report). Additional information about this report can be obtained by contacting Ann Gibbs (agibbs@usgs.gov). A formal evaluation performed by Quantum Spatial, Incorporated (QSI; 2019) compared these data to vertical control points, 214 in total, which were limited to the villages between Cape Prince of Wales and Point Hope. The data were also compared to lidar collected in 2004. Control points were used to quantifiably evaluate the vertical accuracy of these data. The horizontal accuracy of these data could not be reliable quantified, though a visual assessment indicated that these data align with previously collected lidar data. Quantum Spatial, Incorporated (QSI; 2019) compared elevation data in this dataset to elevation measurements from other sources that cover the same area and were found to be consistent except near areas of moving water. Data also include returns from vegetation/the canopy. Shallow underwater reconstructions have not been corrected for parallax. Structure-from-motion photogrammetry utilizes overlapping photographs, which can cause moving water surfaces to appear unrealistic. In some rare cases, images of water and anomalous elevation may appear in spatially unrealistic places. These artifacts were not removed from this dataset, but are very recognizable, especially when combined with the related coincident orthoimagery dataset. Users are advised to become familiar with the entire metadata document. Formal horizontal accuracy checks were not possible, but visual evaluations conducted by Quantum Spatial, Incorporated (QSI; 2019) confirmed that these data align well with other orthoimagery and lidar data. Gibbs and others (2019) used a horizontal uncertainty value of 0.3 meters. Quantum Spatial, Incorporated (QSI; 2019) compared a subset of this dataset to vertical control points, 214 in total, which were limited to the villages between Cape Prince of Wales and Point Hope. Although this comparison was limited to a small subset of data, the full extent of this dataset was collected and processed using consistent methods, so it is reasonable to expect similar accuracy values throughout the dataset. The evaluation determined that these data were on average 28 cm lower than the elevation of the GCPs, with a RMSE of 38 cm. These accuracy values do not include elevation data collected over water, which should not be used. Photographs were collected using a Nikon D800E with 24 mm lens mounted to a vertical camera port and connected to a survey grade GPS (Trimble 5700), which records an event marker for each photo, allowing for positional accuracy of less than 10 cm. The camera and GPS system was fit to a Cessna 170B, from which the photos were collected (Nolan and others, 2015). Photographs were primarily collected by flying two passes parallel to the shoreline in a flight pattern that achieved approximately 60 percent side lap and 80 percent end lap between photographs. Acquisition methods followed those outlined in Nolan and others (2015), with the exception of the number of passes made by the aircraft, which in this case was two instead of four. 20160904 Dr. Matt Nolan Fairbanks Fodar Owner mailing

PO Box 82416

Fairbanks AK 99708 907-978-0542 info@fairbanksfodar.com Photographs were processed to optimize exposure and contrast. Photograph position GPS data were post-processed using precise point positioning (PPP) due to the absence of a nearby available GPS base station network. The overlapping aerial photos and GPS positions were input into Agisoft Photoscan Structure-from-Motion software. Data were processed in blocks, based in part on the time the imagery was collected. Agisoft generated point clouds, digital elevation models (DEMs), and orthoimagery, which were output in smaller blocks to make the data more manageable. More information about the processing steps used to generate this dataset are described in Nolan and other, 2015. 20160904 Dr. Matt Nolan Fairbanks Fodar Owner mailing

PO Box 82416

Fairbanks AK 99708 907-978-0542 info@fairbanksfodar.com GDAL v3.3.1 (accessed February, 2022; https://gdal.org) was used to convert the DEMs to cloud optimized geotiffs for data publication. The following command was used: gdal_translate ‘infile’ -of COG -stats -co BLOCKSIZE=256 -co COMPRESS=DEFLATE -co PREDICTOR=YES -co NUM_THREADS=ALL_CPUS -co BIGTIFF=YES. 20220117 Alexander Snyder U.S. Geological Survey Oceanographer Mailing

2885 Mission Street

Santa Cruz CA 95060 831-427-4450 agsnyder@usgs.gov The single metadata file describing data spanning the ocean shoreline of Alaska from Icy Cape to Cape Prince of Wales was split into three separate metadata files: Icy Cape to Kivalina, Kivalina to Cape Espenberg, and Cape Espenberg to Cape Prince of Wales. The file names, titles, abstract, bounding coordinates, place keywords, attribute values online linkage, transfer size, and network resource names were updated to describe the geographically defined section of data associated with the metadata file. 20260305 Manda Au U.S. Geological Survey Data Management Specialist Mailing

2885 Mission Street

Santa Cruz CA 95060 831-460-7575 mau@usgs.gov Raster Pixel Universal Transverse Mercator 3 0.999600 -165.000000 0.000000 500000.000000 0.000000 row and column 0.20 0.20 meters NAD83_National_Spatial_Reference_System_2011 Geodetic Reference System 80 6378137.000000 298.257222101 North American Vertical Datum of 1988 Geoid 12B 0.001 meters Explicit elevation coordinate included with horizontal coordinates Single-band GeoTIFF Raster Single-band, 32-bit, floating point rasters with surface elevation data. Surface elevation refers to the highest surface visible from aerial imagery (for example, exposed ground, rooftops, tree canopy). Producer defined Value Orthometric height relative to the North American Vertical Datum of 1988. Producer defined -162.89 207.80 -32767 No data Producer defined These attribute values represent all digital elevation model rasters in this data release. Filenames are a unique identifier that describes certain attributes of the file, including the region, processing group, data type, grid size, and format. For example, the filename ‘shish_C_dem_20cm-4-2x_cog’ refers to data that is somewhat close to the town of Shishmaref (‘shish’), processed with other files in group ‘C’, contains orthoimagery (‘ortho’) data, represented as a raster with cell size ‘20cm’, uniquely identified as ‘4-2, and stored as a Cloud Optimized GeoTIFF (‘cog’). Producer defined U.S. Geological Survey - ScienceBase mailing and physical

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Denver CO 80225 1-888-275-8747 sciencebase@usgs.gov These data are available in cloud optimized GeoTIFF format and include CSDGM FGDC compliant metadata. All data use the horizontal and vertical coordinate reference systems NAD83(2011)/UTM Zone 3N and NAVD88 (m) using geoid 12B. Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. GeoTIFF Files contain high-resolution digital elevation models as cloud optimized GeoTIFFs. Filename indicates raster resolution in centimeters and general region of data coverage. Deflate compression used in COG generation. Most GIS software can read this compression format without any extra steps from the user. 46420 https://www.sciencebase.gov/catalog/item/62854aebd34e3bef0c9a6b3b https://doi.org/10.5066/P9PGJNE9 Data can be downloaded using the Network_Resource_Name links. The first link points to the landing page where the digital elevation model(DEMs) data can be downloaded and includes the metadata. The last link points to the landing page for the entire data release from which other data types can be accessed. None. These data can be viewed with Geographic Information Systems (GIS) software or other software capable of displaying geospatial raster data. 20260305 U.S. Geological Survey, Pacific Coastal and Marine Science Center PCMSC Science Data Coordinator mailing and physical

2885 Mission Street

Santa Cruz CA 95060 831-427-4747 pcmsc_data@usgs.gov Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998