{"action":"create","ckan_id":null,"date_created":"Sat, 14 Feb 2026 20:33:41 GMT","date_finished":null,"harvest_job_id":"e0f41b31-a68d-43ff-8093-27a46dae0336","harvest_source_id":"31f41541-38a0-400b-b240-10ebcb0acd9a","id":"865c7b41-7810-4dc4-8d99-50697c2b4340","identifier":"https://dggs.alaska.gov/webpubs/metadata/RDF2011-3_snow.xml","parent_identifier":null,"source_hash":"00f46886f1df06f87d52c3f7ef69fc188537e0aa772f39102be795db6177764b","source_raw":"\n\n\n\n\nHubbard, T.D.\nBraun, M.L.\nWestbrook, R.E.\nGallagher, P.E.\n2011\nHigh-resolution lidar data for infrastructure corridors, Mount Hayes Quadrangle, Alaska\nvector digital data, document\n\nRaw Data File\nRDF 2011-3A\n\n\nFairbanks, Alaska USA\nState of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys\n\nhttp://dx.doi.org/10.14509/22723\n\n\nHubbard,T.D.\nKoehler, R.D.\nCombellick, R.A.\n2011\nHigh-resolution lidar data for Alaska infrastructure corridors\nvector digital data, document\n\nRaw Data File\nRDF 2011-3\n\n\nFairbanks, AK USA\nState of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys\n\nhttp://dx.doi.org/10.14509/22722\n\n\n\n\n\nIn advance of design, permitting, and construction of a pipeline to deliver North Slope natural gas to out-of-state customers and Alaska communities, the Division of Geological & Geophysical Surveys (DGGS) has acquired lidar (Light Detection and Ranging) data along proposed pipeline routes, nearby areas of infrastructure, and regions where significant geologic hazards have been identified. Lidar data will serve multiple purposes, but have primarily been collected to (1) evaluate active faulting, slope instability, thaw settlement, erosion, and other engineering constraints along proposed pipeline routes, and (2) provide a base layer for the state-federal GIS database that will be used to evaluate permit applications and construction plans. This shapefile identifies areas where lidar points have been classified as snow or where snow was thought to exist based on evaluation of bare-earth DEM's and intensity images.\nShapefile meant to identify areas within the lidar dataset that may contain snow. Ground elevations may be less accurate in areas of snow.\n\nInformation about accuracy and quality of lidar data can be found in quality control reports provided by DOGAMI and delivery reports provided by Watershed Sciences, Inc. Individual reports were provided for each delivery set and have been combined by DGGS into comprehensive quality control and delivery reports. These documents are organized by according to how data were delivered to DGGS. A description of information pertaining to down-loadable files can be found in the quality control and delivery reports. The DGGS metadata standard extends the FGDC standard to include elements that are required to facilitate our internal data management. These elements, referred to as "layers," group and describe files that have intrinsic logical or topological relationships. This dataset is described as a single layer. Attribute information for the layer is included in this metadata file under the "Entity_and_Attribute_Information" section. The layer is titled: \t\n>snow:\tPolygons representing areas of snow\n\n\n\n\n\n2010\n2011\n\n\nground condition\n\n\nComplete\nAs needed\n\n\n\n-145.872802\n-145.531953\n63.738310\n63.171531\n\n\n\n\nISO 19115 Topic Category\ngeoscientificInformation\n\n\nAlaska Division of Geological & Geophysical Surveys\nAlaska Pipeline\nGasline\nGeomorphology\nLidar\nProposed Natural Gas Pipeline\nRemote Sensing\n\n\nAlaska Division of Geological & Geophysical Surveys\nMount Hayes Quadrangle\nAlaska Highway Corridor\nAlaska, State of\nTrans-Alaska Pipeline\n\n\nThis report, map, and/or dataset is available directly from the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys (see contact information below).\nAny hard copies or published datasets utilizing these datasets shall clearly indicate their source. If the user has modified the data in any way, the user is obligated to describe the types of modifications the user has made. The user specifically agrees not to misrepresent these datasets, nor to imply that changes made by the user were approved by the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys. The State of Alaska makes no express or implied warranties (including warranties for merchantability and fitness) with respect to the character, functions, or capabilities of the electronic data or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products or any failure thereof or otherwise. In no event will the State of Alaska's liability to the Requestor or anyone else exceed the fee paid for the electronic service or product.\n\n\n\nAlaska Division of Geological & Geophysical Surveys\nJames Weakland\n\nGIS Analyst\n\nmailing and physical\n
3354 College Road
\nFairbanks\nAK\n99709-3707\nUSA\n\n(907)451-5029\n(907)451-5020\ndggsgis@alaska.gov\n8 am to 4:30 pm, Monday through Friday, except State holidays\n\n\nData collection was supported by funding from the Department of Natural Resources (DNR), Division of Geological & Geophysical Surveys (DGGS), the Alaska Gas Pipeline Project Office, the Office of the Federal Coordinator, and the Alaska Gasline Development Corporation (AGDC). Lidar data were collected and processed by Watershed Sciences, Inc. of Corvallis, OR. Survey data were collected by McClintock Land Associates of Eagle River, AK. Lidar data and derivative products were checked for quality, completeness, and accuracy by State of Oregon Department of Geology & Mineral Industries based in Portland, OR.\nMicrosoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcCatalog 9.3.1.3000\n\n\n\nThe accuracy of the snow polygons is dependent on the accuracy of the collected lidar data and inspection of the bare-earth DEM's and intensity images. This shapefile is only to be used as a reference and was not evaluated for accuracy.\n\nLidar DEM's and intensity images were inspected to be consistent when identifying areas of snow. See process steps for more detail.\nSnow polygons were not checked for completeness. Polygons are only meant to be used as a reference in areas where there was detectable snow cover.\n\n\nHorizontal accuracy is dependant on the accuracy of the collected lidar data and the interpretations made from bare-earth DEM's and intensity imagery. Therefore the accuracy can be no greater than the accuracy of the lidar. True horizontal accuracy is regarded as a product of the lidar ground footprint. Lidar is referenced to co-acquired GPS base station data that have accuracies far greater than the value of the lidar footprint. The ground footprint is equal to 1/3333rd of the above-ground flying height. The ground footprint for data collected for this project exceeds typical accuracy of ground control used to reference the lidar data (less than 0.01 meters). Project specifications require the lidar footprint to be between 0.15 and 0.40 meters. Refer to the lidar QC report and lidar delivery report for additional information on horizontal accuracy for individual delivery areas.\n\n\n\n\nAcquisition: The lidar data were collected between September and October 2010 and between May and July 2011. The survey used the Leica ALS60 system. Near-nadir scan angles were used to increase penetration of vegetation to ground surfaces. Ground-level GPS and aircraft IMU were collected during the flight.\n2010, 2011\n\n\nProcessing lidar data: (1) Flight lines and data were reviewed to ensure complete coverage of the study area and positional accuracy of the laser points. (2) Laser point-return coordinates were computed using ALS Post Processor software, IPAS Pro GPS/INS software, and Waypoint GPS, based on independent data from the lidar system, IMU, and aircraft. (3) The raw lidar file was assembled into flight lines per return with each point having an associated x, y, and z coordinate. (4) Visual inspection of swath-to-swath laser point consistencies in the study area were used to perform manual refinements of system alignment. (5) Custom algorithms were designed to evaluate points between adjacent flight lines. Automated system alignment was computed based on randomly selected swath-to-swath accuracy measurements that consider elevation, slope, and intensities. Specifically, refinement in the combination of system pitch, roll, and yaw-offset parameters optimize internal consistency. (6) Noise (e.g., pits and birds) was filtered using ALS post processing software, based on known elevation ranges, and included the removal of any cycle slips.\n2010, 2011, 2012\n\n\nCreation of bare-earth DEMs: (1) The TerraScan software suite was used to classify near-ground points. Geometric constraints were used to remove all points not near the earth. The resulting bare-earth ground model was then visually inspected and additional ground modeling was performed in site-specific areas to improve ground detail. (2) The corrected and filtered return points were compared to the real-time kinematic (RTK) ground survey points collected to verify the vertical and horizontal accuracies. (3) Points were output as laser points, TINed and GRIDed.\n2010, 2011, 2012\n\n\nCreation of lidar intensity images: (1) Laser points were then broken into tiles related to their quadrangle and output as GeoTiffs, colored (0-255) by intensity value.\n2010 and 2011, 2012\n\n\nBare earth DEMs and intensity images were used to identify areas of potential snow. In some areas of the project, snow could not be avoided during acquisition. Lidar returns that were identifiable as snow were reclassified into a new "snow" class. In areas where snow completely obstructed the ground, snow points were retained in the ground model to avoid expansive interpolation across snow fields. In areas where snow prevented laser penetration, ground elevations may be offset from the true ground. A shapefile delineating areas of snow was created. The shapefile attribution includes a field designating each area as "classified" - meaning valid ground returns exist beneath the snow, or "suspected" - meaning no valid ground returns exist, but the area was identified as snow using the return intensity pattern. Because of temporal differences in neighboring flight mission areas, a 'stair step' artifact occurs in quad XMHA4 as a result of snow melt on the river valley between June 7th and June 27th, 2011.\n2011, 2012\n\n\nA metadata file was created to generally describe to describe the vector polygon files delineating areas of snow within the lidar collection area. .\n2012\n\n\n\n\nvector\n\n\n\n\n\nUniversal Transverse Mercator\n\n6\n\n0.999600\n-147.000000\n0.000000\n500000.000000\n0.000000\n\n\n\n\ncoordinate pair\n\n0.000001\n0.000001\n\nmeters\nsnow\n\n\n\nNorth American Datum of 1983\nGeodetic Reference System 80\n6378137\n298.257222\n\n\n\n\n\n\nrdf2011-3-snow\nPolygons representing areas of snow.\nthis report\nsnow\n\n\nsnow\nIndicates level of certainty associated with polygons representing areas of snow\nDepartment of Natural Resources, Division of Geological & Geophysical surveys and Watershed Sciences, Inc.\n\n\nclassed\nAreas of snow with valid ground points below\nWatershed Sciences, Inc. and Alaska Division of Geological & Geophysical Surveys\n\n\n\n\nsuspected\nAreas indicative of snow without valid ground points below. Snow was identified based on the patterns of the intensity returns\nWatershed Sciences, Inc. and Alaska Division of Geological & Geophysical Surveys\n\n\n\n\n\n\n\n\n\nAlaska Division of Geological & Geophysical Surveys\n\n\nmailing and physical\n
3354 College Road
\nFairbanks\nAK\n99709-3707\nUSA\n\n(907)451-5020\n(907)451-5050\ndggspubs@alaska.gov\n8 am to 4:30 pm, Monday through Friday, except State holidays\nPlease view our website (http://www.dggs.alaska.gov) for the latest information on available data. Please contact us using the e-mail address provided above when possible.\n\n\nRDF 2011-3A\nThe State of Alaska makes no express or implied warranties (including warranties of merchantability and fitness) with respect to the character, function, or capabilities of the electronic services or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity, whether from the use of the electronic services or products, any failure thereof, or otherwise, and in no event will the State of Alaska's liability to the requestor or anyone else exceed the fee paid for the electronic service or product.\n\nDGGS publications are available as free online downloads or you may purchase paper hard-copies or digital files on CD/DVD or other digital storage media by mail, phone, fax, or email from the DGGS Fairbanks office. To purchase this or other printed reports and maps, contact DGGS by phone (907-451-5020), e-mail (dggspubs@alaska.gov), or fax (907-451-5050). Payment accepted: Cash, check, money order, VISA, or MasterCard. Turnaround time is 1-2 weeks unless special arrangements are made and an express fee is paid. Shipping charge will be the actual cost of postage and will be added to the total amount due. Contact us for the exact shipping amount.\nContact DGGS for current pricing\n\n\n\n\nvector digital data\n\n\n\n\n\nhttp://dx.doi.org/10.14509/22723\n\n\n\n\n\nFree download\n\n\n\n20120726\n\n\n\nMetadata manager\n\n\nmailing and physical\n
3354 College Road
\nFairbanks\nAK\n99709-3707\nUSA\n\n(907)451-5020\n\n\nFGDC Content Standard for Digital Geospatial Metadata\nFGDC-STD-001-1998\nIf the user has modified the data in any way they are obligated to describe the types of modifications they have performed in the supporting metadata file. User specifically agrees not to imply that changes they made were approved by the Alaska Department of Natural Resources or Division of Geological & Geophysical Surveys.\n\nhttp://www.dggs.alaska.gov/metadata/dggs.ext\ndggs metadata extensions\n\n\n\n","source_transform":null,"status":"error"}