{"action":"create","ckan_id":null,"date_created":"Sat, 28 Feb 2026 20:44:04 GMT","date_finished":null,"harvest_job_id":"6ffa3b4c-5787-478c-b13f-c34182db1fa4","harvest_source_id":"31f41541-38a0-400b-b240-10ebcb0acd9a","id":"4978a162-6805-48e4-aa54-23b0172b7641","identifier":"https://dggs.alaska.gov/webpubs/metadata/RDF2020-5.xml","parent_identifier":null,"source_hash":"fa4191c4dfbbee926504f3ea79d0c3be0c897272b30f8375507c570113fcc462","source_raw":"\n\n\n\n\nDaanen, R.D.\nWolken, G.J.\nHerbst, A.M.\n2020\nHigh-resolution lidar data from the west Susitna area, Southcentral, Alaska\nimagery\n\nRaw Data File\nRDF 2020-5\n\n\nFairbanks, Alaska, United States\nAlaska Division of Geological & Geophysical Surveys\n\n7 p.\nhttp://doi.org/10.14509/30455\n\n\n\nThe Alaska Division of Geological & Geophysical Surveys used airborne lidar to produce a digital terrain model (DTM) and digital surface model (DSM) for the west Susitna area, about 65 km (40 mi) west of Wasilla, Alaska. Airborne data were collected November 4-10, 2019, and subsequently processed in Terrasolid and ArcGIS. Ground control data were concurrently collected by DGGS. All files can be downloaded free of charge from the Alaska Division of Geological & Geophysical Surveys website (http://doi.org/10.14509/30455).\nThis dataset includes point cloud data and two 32-bit raster elevation models that cover an area of interest for proposed infrastructure development in the west Susitna region.\n\n>point cloud data: Classified lidar values. Points were classified in accordance with ASPRS 2014 guidelines. \t\n>digital surface model: DSMs represent surface elevations, as they appear to the naked eye. They include the heights of vegetation, buildings, bridges, etc. The DSM is a single band, 32-bit GeoTif file, with a ground sample distance of .5 meters. No Data value is set to -3.40282306074e+038.\t\n>digital terrain model: DTMs represent surface elevations of ground surfaces, excluding vegetation, bridges, buildings, etc. The DTM is a single-band, 32-bit float GeoTIFF file, with a ground sample distance of .5 meters. No Data value is set to -3.40282306074e+038.\n\n\n\n\n\n2017\n\n\nground condition\n\n\ncomplete\nNone planned\n\n\n\n-151.770872\n-150.594323\n61.941196\n61.106528\n\n\n\n\nISO 19115 Topic Category\ngeoscientificInformation\n\n\nAlaska Division of Geological & Geophysical Surveys\nAerial\nAerial Geology\nDigital Surface Model (DSM)\nDigital Terrain Model\nElevation\nEngineering\nEngineering Geology\nGeologic\nGeology\nGeomorphology\nGeotechnical\nLiDAR\nPoint Cloud Data\nRaster Image\nRemote Sensing\nSurface\nSurficial\nSurficial Geology\nTopography\n\n\nAlaska Division of Geological & Geophysical Surveys\nAlexander Creek\nBates Creek\nBear Creek\nBeluga River\nCanyon Creek\nCanyon Lake\nClear Creek\nCoffee Creek\nDeep Creek\nDog Lake\nFriday Creek\nOlson Creek\nPretty Creek\nQuartz Creek\nSaturday Creek\nSkwentna River\nSusitna\nTalachulitna Creek\nTalachulitna River\nTexas Creek\nThreemile Creek\nThursday Creek\nTrail Creek\nTukallah Lake\nViapan Lake\nWasilla\nWolverine Creek\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\n\nMetadata Manager\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\n\n\nThese data were collected and processed by the Alaska Division of Geological and Geophysical Surveys staff with funding from the Alaska Industrial Development and Export Authority.\n\n\n\nAirborne data were collected on November 4-10, 2019. Weather conditions were generally sub-optimal throughout the survey, requiring operations to take place in thick fog and low-lying clouds, at the risk of increased levels of noise in the product. Snow was present across the majority of the study area surface and accumulated throughout the survey period, especially in the northernmost section. Weather conditions and snow cover resulted in variability of point density throughout the study area. See accompanying report for further discussion of data verification procedures.\n\nThe tests and processing methods used to ensure data consistency are described in the accompanying report.\nElevation surfaces interpolated from areas with a point density of fewer than 1pts/m^2 were classified as nodata. This data release is complete.\n\n\nTrimble R8 and R9 RTK GPS systems were used to collect ground control points (GCPs). Seventy-five checkpoints were used to calculate a vertical accuracy of 39 cm RMSE. Internal consistency for the point cloud data was measured at 6.5cm across the project. Points were adjusted for accuracy, according to OPUS corrections, in Trimble Business Center. See accompanying report for a table of checkpoints and further discussion of factors impacting the certainty of data locations.\n\n\nSeventy-five checkpoints were used to calculate a vertical accuracy of 39 cm RMSE. Relative accuracy was evaluated as the interswath consistency and was measured at 2.1 cm RMSE. The quality of the data is the average elevation compared to an independent dataset. The second aspect of the quality of the data is related to point density distribution over the survey area. The average point density is 10.23 points per square meter. A table of checkpoints and errors is provided in the accompanying report.\n\n\n\n\nData acquisition - DGGS operates a Riegl VUX1-LR lidar integrated with a GNSS and Northrop Grumman IMU system. The integration was designed by Phoenix LiDAR systems. The sensor is capable of collecting up to 820,000 points per second over a distance of 150 m. This survey was flown at a pulse rate between 200,000 and 400,000 pulses per second, at a scan rate between 80 and 150 loops per second. The average pulse spacing was 31.27 cm and the average density was 10.23 pts/m2. This survey was flown with an average elevation of 1,000 m above ground level and a ground speed of approximately 40 m/s with a fixed wing aircraft configuration, using a Cessna 185 aircraft. The scan angle was set from 55 to 305 degrees. Airborne data were collected November 4-10, 2019. Weather conditions were generally sub-optimal throughout the survey, requiring operations to take place in thick fog and low-lying clouds, at the risk of increased levels of noise in the product. Snow was present across the majority of the study area surface and accumulated throughout the survey period, especially in the northernmost section.\n2019\n\n\nPoint classification - Point cloud data was run through SDCimport software for initial filtering and disambiguation of errors. Once filtered, the point cloud and trajectory data were fused together by integrating IMU and GPS information. Points were classified in accordance with ASPRS 2014 guidelines. A significant amount of noise, due to snow and weather conditions during the survey, was separated from the rest of the data and designated to class 8, model keypoints. All classified points were vertically transformed to maintain a mean offset fewer than 10 cm from surveyed ground control.\n2020\n\n\nRaster products - Raster products were produced from las files in ArcMap and were clipped according to a lidar point density threshold of 8pts/m2. DTM and DSM were created using a tin-based method.\n2020\n\n\n\n\nraster\n\n\n\n\n\nUniversal Transverse Mercator\n\n5\n\n0.999600\n-153\n0\n500000.000000\n0\n\n\n\n\ncoordinate pair\n\n.00000001\n.00000001\n\nMeters\n\n\n\nNorth American Datum of 1983\nGRS 80\n6378137\n298.257222101000025\n\n\n\n\nNAVD88, GEOID12B\n0.5\nmeters\nExplicit elevation coordinate included with horizontal coordinates\n\n\n\n\n\n\npoint cloud data\nClassified lidar values. Points were classified in accordance with ASPRS 2014 guidelines.\nAlaska Division of Geological & Geophysical Surveys (DGGS)\npoint cloud data\n\n\n\n\ndigital surface model\nDSMs represent surface elevations, as they appear to the naked eye. They include the heights of vegetation, buildings, bridges, etc. The DSM is a single band, 32-bit GeoTif file, with a ground sample distance of .5 meters. No Data value is set to -3.40282306074e+038.\nAlaska Division of Geological & Geophysical Surveys (DGGS) and National Oceanic & Atmospheric Administration\ndigital surface model\n\n\n\n\ndigital terrain model\nDTMs represent surface elevations of ground surfaces, excluding vegetation, bridges, buildings, etc. The DTM is a single-band, 32-bit float GeoTIFF file, with a ground sample distance of .5 meters. No Data value is set to -3.40282306074e+038.\nAlaska Division of Geological & Geophysical Surveys (DGGS) and National Oceanic & Atmospheric Administration\ndigital terrain model\n\n\n\n\n\n\n\nAlaska Division of Geological & Geophysical Surveys\n\nMetadata Manager\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\n\n\nRDF 2020-5\nThe State of Alaska makes no expressed 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\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\nimagery\n\n\n\n\n\nhttp://doi.org/10.14509/30455\n\n\n\n\n\nFree download\n\n\n\n20200624\n\n\n\nAlaska Division of Geological & Geophysical Surveys\nSimone Montayne\n\nMetadata Manager\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\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"}