Identification_Information: Citation: Citation_Information: Originator: Hubbard, T.D. Originator: Braun, M.L. Originator: Westbrook, R.E. Originator: Gallagher, P.E. Publication_Date: 2011 Title: High-resolution lidar data for infrastructure corridors, Mount Hayes Quadrangle, Alaska Geospatial_Data_Presentation_Form: vector digital data, document Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2011-3A Publication_Information: Publication_Place: Fairbanks, Alaska USA Publisher: State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys Online_Linkage: http://dx.doi.org/10.14509/22723 Larger_Work_Citation: Citation_Information: Originator: Hubbard,T.D. Originator: Koehler, R.D. Originator: Combellick, R.A. Publication_Date: 2011 Title: High-resolution lidar data for Alaska infrastructure corridors Geospatial_Data_Presentation_Form: vector digital data, document Series_Information: Series_Name: Raw Data File Issue_Identification: RDF 2011-3 Publication_Information: Publication_Place: Fairbanks, AK USA Publisher: State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys Online_Linkage: http://dx.doi.org/10.14509/22722 Description: Abstract: In 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. Purpose: Shapefile meant to identify areas within the lidar dataset that may contain snow. Ground elevations may be less accurate in areas of snow. Supplemental_Information: Information 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: >snow: Polygons representing areas of snow Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 2010 Ending_Date: 2011 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: As needed Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -145.872802 East_Bounding_Coordinate: -145.531953 North_Bounding_Coordinate: 63.738310 South_Bounding_Coordinate: 63.171531 Keywords: Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: geoscientificInformation Theme: Theme_Keyword_Thesaurus: Alaska Division of Geological & Geophysical Surveys Theme_Keyword: Alaska Pipeline Theme_Keyword: Gasline Theme_Keyword: Geomorphology Theme_Keyword: Lidar Theme_Keyword: Proposed Natural Gas Pipeline Theme_Keyword: Remote Sensing Place: Place_Keyword_Thesaurus: Alaska Division of Geological & Geophysical Surveys Place_Keyword: Mount Hayes Quadrangle Place_Keyword: Alaska Highway Corridor Place_Keyword: Alaska, State of Place_Keyword: Trans-Alaska Pipeline Access_Constraints: This 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). Use_Constraints: Any 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. Point_of_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Alaska Division of Geological & Geophysical Surveys Contact_Person: James Weakland Contact_Position: GIS Analyst Contact_Address: Address_Type: mailing and physical Address: 3354 College Road City: Fairbanks State_or_Province: AK Postal_Code: 99709-3707 Country: USA Contact_Voice_Telephone: (907)451-5029 Contact_Voice_Telephone: (907)451-5020 Contact_Electronic_Mail_Address: dggsgis@alaska.gov Hours_of_Service: 8 am to 4:30 pm, Monday through Friday, except State holidays Data_Set_Credit: Data 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. Native_Data_Set_Environment: Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcCatalog 9.3.1.3000 Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: The 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. Logical_Consistency_Report: Lidar DEM's and intensity images were inspected to be consistent when identifying areas of snow. See process steps for more detail. Completeness_Report: Snow polygons were not checked for completeness. Polygons are only meant to be used as a reference in areas where there was detectable snow cover. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Horizontal 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. Lineage: Process_Step: Process_Description: Acquisition: 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. Process_Date: 2010, 2011 Process_Step: Process_Description: Processing 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. Process_Date: 2010, 2011, 2012 Process_Step: Process_Description: Creation 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. Process_Date: 2010, 2011, 2012 Process_Step: Process_Description: Creation 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. Process_Date: 2010 and 2011, 2012 Process_Step: Process_Description: Bare 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. Process_Date: 2011, 2012 Process_Step: Process_Description: A metadata file was created to generally describe to describe the vector polygon files delineating areas of snow within the lidar collection area. . Process_Date: 2012 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: vector Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Grid_Coordinate_System: Grid_Coordinate_System_Name: Universal Transverse Mercator Universal_Transverse_Mercator: UTM_Zone_Number: 6 Transverse_Mercator: Scale_Factor_at_Central_Meridian: 0.999600 Longitude_of_Central_Meridian: -147.000000 Latitude_of_Projection_Origin: 0.000000 False_Easting: 500000.000000 False_Northing: 0.000000 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: coordinate pair Coordinate_Representation: Abscissa_Resolution: 0.000001 Ordinate_Resolution: 0.000001 Planar_Distance_Units: meters Planar_Coordinate_Layer_Name: snow Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1983 Ellipsoid_Name: Geodetic Reference System 80 Semi-major_Axis: 6378137 Denominator_of_Flattening_Ratio: 298.257222 Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Attribute_Layer_Name: snow Entity_Type_Label: rdf2011-3-snow Entity_Type_Definition: Polygons representing areas of snow. Entity_Type_Definition_Source: this report Attribute: Attribute_Label: snow Attribute_Definition: Indicates level of certainty associated with polygons representing areas of snow Attribute_Definition_Source: Department of Natural Resources, Division of Geological & Geophysical surveys and Watershed Sciences, Inc. Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: classed Enumerated_Domain_Value_Definition: Areas of snow with valid ground points below Enumerated_Domain_Value_Definition_Source: Watershed Sciences, Inc. and Alaska Division of Geological & Geophysical Surveys Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: suspected Enumerated_Domain_Value_Definition: Areas indicative of snow without valid ground points below. Snow was identified based on the patterns of the intensity returns Enumerated_Domain_Value_Definition_Source: Watershed Sciences, Inc. and Alaska Division of Geological & Geophysical Surveys Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: Alaska Division of Geological & Geophysical Surveys Contact_Address: Address_Type: mailing and physical Address: 3354 College Road City: Fairbanks State_or_Province: AK Postal_Code: 99709-3707 Country: USA Contact_Voice_Telephone: (907)451-5020 Contact_Facsimile_Telephone: (907)451-5050 Contact_Electronic_Mail_Address: dggspubs@alaska.gov Hours_of_Service: 8 am to 4:30 pm, Monday through Friday, except State holidays Contact_Instructions: Please 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. Resource_Description: RDF 2011-3A Distribution_Liability: The 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. Standard_Order_Process: Non-digital_Form: DGGS 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. Fees: Contact DGGS for current pricing Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: vector digital data Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: http://dx.doi.org/10.14509/22723 Fees: Free download Metadata_Reference_Information: Metadata_Date: 20120726 Metadata_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Metadata manager Contact_Address: Address_Type: mailing and physical Address: 3354 College Road City: Fairbanks State_or_Province: AK Postal_Code: 99709-3707 Country: USA Contact_Voice_Telephone: (907)451-5020 Metadata_Standard_Name: FGDC Content Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Use_Constraints: If 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. Metadata_Extensions: Online_Linkage: http://www.dggs.alaska.gov/metadata/dggs.ext Profile_Name: dggs metadata extensions