Identification_Information: Citation: Citation_Information: Originator: Smith, B.D., Cannia, J.C. Publication_Date: 2008 Title: Firth HEM data Geospatial_Data_Presentation_Form: vector and raster digital data Online_Linkage: USGS OFR 2008 1018 Description: Abstract: This report is a digital data release for a helicopter electromagnetic and magnetic survey that was conducted during March 2007 in three 93-square-kilometer (36-square-mile) areas of eastern Nebraska as part of a joint State of Nebraska and U.S. Geological Survey study. The objective of the survey is to improve the understanding of the relationship between surface-water and ground-water systems critical to developing water resource management programs. The electromagnetic equipment consisted of six different coil-pair orientations that measured electrical resistivity at separate frequencies from about 400 hertz to about 115,000 hertz. The electromagnetic data were converted to electrical resistivity geo-referenced grids and maps, each representing different approximate depths of investigation for each area. The range of subsurface investigation is comparable to the depth of shallow aquifers. The three areas selected for the study, Ashland, Firth, and Oakland, have glacial terrains and bedrock that typify different hydrogeologic settings for surface water and ground water in eastern Nebraska. The geophysical and hydrologic information from U.S. Geological Survey studies are being used by resource managers to develop ground-water resource plans for the area. Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 2008 Currentness_Reference: ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: NAD83, UTM14N, meters Bounding_Coordinates: West_Bounding_Coordinate: 698796.2 East_Bounding_Coordinate: 707510.9 North_Bounding_Coordinate: 4501647.0 South_Bounding_Coordinate: 4484804.8 Keywords: Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: geoscientificInformation Theme_Keyword: imageryBaseMapsEarthCover Theme_Keyword: environment Place: Place_Keyword_Thesaurus: Geographic Names Information System Place_Keyword: Nebraska Place_Keyword: Firth Access_Constraints: None Use_Constraints: None Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Bruce D. Smith Contact_Organization: U.S. Geological Survey Contact_Position: Geophysicist Contact_Address: Address_Type: mailing address Address: PO Box 25046,MS973 Address: Denver Federal Center City: Denver State_or_Province: CO Postal_Code: 80225 Country: USA Contact_Voice_Telephone: 303.236.1399 Contact_Electronic_Mail_Address: bsmith@usgs.gov Contact_Instructions: Contact via email Native_Data_Set_Environment: Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.2.2.1350 Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: Arc feature attribute values were inspected and found to be consistently coded as described in the Entity and Attribute section. Logical_Consistency_Report: Using ArcGIS tools and routines all arcs were checked for node errors, overshoots, undershoots, dangles, intersections, and duplicate features. Completeness_Report: This data set includes only the study area for the HEM investigation conducted near Firth, Nebraska. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Horizontal accuracy was not assessed. Lineage: Process_Step: Process_Description: Airborne geophysical data processing described in OFR 2008-1018 Process_Date: field 20070326 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Vector Point_and_Vector_Object_Information: SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: String Point_and_Vector_Object_Count: Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Map_Projection: Map_Projection_Name: Transverse Mercator Transverse_Mercator: Scale_Factor_at_Central_Meridian: 0.999600 Longitude_of_Central_Meridian: -99.000000 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: 1.49693125 Ordinate_Resolution: 1.49693125 Planar_Distance_Units: meters Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1983 Ellipsoid_Name: Geodetic Reference System 80 Semi-major_Axis: 6378137.000000 Denominator_of_Flattening_Ratio: 298.257222 Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: Polyline Entity_Type_Definition: bounding area of airborne survey maps Entity_Type_Definition_Source: U.S. Geological Survey Attribute: Attribute_Label: FID Attribute_Definition: Internal feature number. Attribute_Definition_Source: ESRI Attribute_Domain_Values: Unrepresentable_Domain: Sequential unique whole numbers that are automatically generated. Attribute: Attribute_Label: Shape Attribute_Definition: Feature geometry. Attribute_Definition_Source: ESRI Attribute_Domain_Values: Unrepresentable_Domain: Coordinates defining the features. Attribute: Attribute_Label: Handle Attribute_Definition: Unique ID from DXF polyline Attribute_Definition_Source: U.S. Geological Survey Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: xxf Enumerated_Domain_Value_Definition: String of values and text representing the flight path line Enumerated_Domain_Value_Definition_Source: U.S. Geological Survey Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: U.S. Geological Survey Contact_Position: Water Webserver Team Contact_Address: Address_Type: mailing address Address: 12201 Sunrise Valley Drive, MS 440 City: Reston State_or_Province: VA Postal_Code: 20192 Country: USA Contact_Voice_Telephone: 1-888-475-8747 (1-888-ASK-USGS) Contact_Instructions: Contact via email Resource_Description: Downloadable Data Distribution_Liability: Although these data have been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of this data, software, or related materials. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: Shapefile Transfer_Size: 0.324 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: http://water.usgs.gov/GIS/Firth_HEMflight_path_nad83.zip Fees: None Metadata_Reference_Information: Metadata_Date: 20071031 Metadata_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: ?? Contact_Organization: U.S. Geological Survey Contact_Position: ?? Contact_Address: Address_Type: mailing and physical address Address: 5231 S 19th Street City: Lincoln State_or_Province: NE Postal_Code: 68512 Country: USA Contact_Voice_Telephone: 402.328.4100 Contact_Electronic_Mail_Address: xxxx@usgs.gov Contact_Instructions: Contact via email Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Time_Convention: local time Metadata_Extensions: Online_Linkage: http://www.esri.com/metadata/esriprof80.html Profile_Name: ESRI Metadata Profile