Identification_Information: Citation: Citation_Information: Originator: V.E. Langenheim Originator: R.C. Jachens PPublication_Date: 2014 Title: Magnetic data, processing, and maps of Fort Irwin and vicinity, southern California Geospatial_Data_Presentation_Form: point digital data Series_Information: Series_Name: Open-File Report Issue_Identification: 2013-1024–I Publication_Information: Publication_Place: Menlo Park, CA Publisher: U.S. Geological Survey Online Linkage: http://pubs.usgs.gov/of/2013/1024/i/ Description: Abstract: Helicopter magnetic data of the Leach Basin area, aeromagnetic data for the Soda Lake region, magnetic gradients, a grid of the detailed aeromagnetic data, and magnetic susceptibility data for Fort Irwin and vicinity, southern California Digital Files: The database includes an ASCII file containing point magnetic data from the Leach Basin helicopter survey, an ASCII file containing point magnetic data from the Soda Lake aeromagnetic survey, a grid of detailed aeromagnetic data from the Fort Irwin region, two ASCII files with point locations of the local maximum horizontal gradient derived from the magnetic grid, and one of magnetic susceptibility data. This metadata file describes the point magnetic data for Leach Basin survey. Purpose: Magnetic map identifies magnetic features as a basis for geophysical interpretations. Supplemental_Information: This database updates geophysical information originally presented in smaller scale formats and includes detailed aeromagnetic data collected by Aeroquest International using Geometrics G-823A cesium vapor magnetometer for the airborne measurements and ENVI/MAG (Scintrex proton precession magnetometer) for the base station measurements. Lines were flown in a north-south direction and were spaced 400 and 800m apart. Three east-west tie lines were also flown. The nominal ground clearance of the magnetometer bird was 63.2 m, but can be higher in more rugged terrain. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 2010 Ending_Date: 2011 Currentness_Reference: publication date Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -116.873 East_Bounding_Coordinate: -116.359 North_Bounding_Coordinate: 35.6511 South_Bounding_Coordinate: 35.5036 Keywords: Theme: Theme_Keyword: magnetics Theme_Keyword: magnetic anomaly Place: Place_Keyword: southern California Place_Keyword: Mojave Desert Place_Keyword: Fort Irwin Place_Keyword: Leach Lake Access_Constraints: none Use_Constraints: Uses of this digital data should not violate the spatial or attribute resolution of the data. Although the digital form of the data stores location and attribute values to several decimals of precision, the data is subject to the accuracy and precision inherent in the data due to data collection and processing limitations. Where this data is used in combination with other data, the precision and accuracy of the resulting dataset is limited by the precision and accuracy of the input datasets. Acknowledgement of the U.S. Geological Survey and Pacific Gas and Electric Company is appreciated for products derived from these data. Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Victoria Langenheim Contact_Organization: U.S. Geological Survey Contact_Position: geophysicist Contact_Address: Address_Type: physical address Address: 345 Middlefield Rd. City: Menlo Park State_or_Province: CA Postal_Code: 94025 Country: USA Contact_Voice_Telephone: 650-329-5313 Contact_Electronic_Mail_Address: zulanger@usgs.gov Native_Data_Set_Environment: Geosoft Oasis Montaj Native_Data_Set_Environment: Geosoft Oasis Montaj Geophysical data was stored and analyzed on a SUN Ultra4000 UNIX platform Geospatial_Data_Presentation_Form: ascii digital data (aeromagnetic data) Series_Information: Series_Name: U.S. Geological Survey (USGS) Open-File Report Issue_Identification: 2012-XXXX Publication_Information: Publication_Place: Menlo Park, California Publisher: U.S. Geological Survey Online_Linkage: Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: magnetic field values are reported to 0.001 and 0.01 nT Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: GPS accuracy should be less than 3 meters Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: GPS accuracy should be less than 3 meters Lineage: Source_Information: Source_Citation: Citation_Information: Originator: Aeroquest International Publication_Date: 2011 Title: Logistics Report--Leach Basin 2011 Geospatial_Data_Presentation_Form: vector digital data Type_of_Source_Media: disc Source_Citation_Abbreviation: Aeroquest International Report on a Helicopter-Borne AeroTEM system Electromagnetic and Magnetic Survey Process_Step: Process_Description: Refer to Project Report by Aeroquest International Process_Date: 2011 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Point Point_and_Vector_Object_Information: SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: Entity point Point_and_Vector_Object_Count: 266434 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: 0.000001 Longitude_Resolution: 0.000001 Geographic_Coordinate_Units: Decimal degrees Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1983 Ellipsoid_Name: Geodetic Reference System 80 Semi-major_Axis: 6378206.4 Denominator_of_Flattening_Ratio: 298.257 Vertical_Coordinate_System_Definition: Altitude_System_Definition: Altitude_Datum_Name: North American Vertical Datum of 1988 Altitude_Distance_Units: meters Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: LeachMag.xyz Attribute: Attribute_Label: Line Attribute_Definition: line number Attribute_Definition_Source: Aeroquest International Attribute: Attribute_Label: lat Attribute_Definition: latitude coordinate (NAD27 datum) Attribute_Definition_Source: Aeroquest International Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: <3 m Attribute: Attribute_Label: lon Attribute_Definition: longitude coordinate (NAD27 datum) Attribute_Definition_Source: Aeroquest International Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: <3 m Attribute: Attribute_Label: galtf Attribute_Definition: Height above sea level Attribute_Definition_Source: Aeroquest International Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.2 m Attribute: Attribute_Label: Ralt_lag Attribute_Definition: radar height (meters above ground level) Attribute_Definition_Source: Aeroquest International Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 1.5 m Attribute: Attribute_Label: balt Attribute_Definition: barometric altitude Attribute_Definition_Source: Aeroquest International Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 1 m Attribute: Attribute_Label: lalt Attribute_Definition: laser altitude Attribute_Definition_Source: Aeroquest International Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 1 m Attribute: Attribute_Label: magU_raw Attribute_Definition: raw magnetic total field (uncompensated) Attribute_Definition_Source: Aeroquest International Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.1 nT Attribute: Attribute_Label: magU_filt Attribute_Definition: raw magnetic field filtered to remove spikes and corrected for lag of 0.1 seconds Attribute_Definition_Source: Aeroquest International Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.1 nT Attribute: Attribute_Label: basemag Attribute_Definition: measured base station magnetic field Attribute_Definition_Source: Aeroquest International Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.1 nT Attribute: Attribute_Label: magU Attribute_Definition: diurnally-corrected magU_filt magnetic field Attribute_Definition_Source: Aeroquest International Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.1 nT Attribute: Attribute_Label: IGRF Attribute_Definition: Calculated IGRF model Attribute_Definition_Source: Aeroquest International Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.1 nT Attribute: Attribute_Label: maguf Attribute_Definition: IGRF corrected magnetic field (magU) Attribute_Definition_Source: Aeroquest Internationals Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.2 nT Distribution_Information: Distributor: U.S. Geological Survey Resource_Description: Downloadable Data Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: ASCII with first line being a header (denoted by "\") Transfer_Size: 347237415 Network_Resource_Name: http://pubs.usgs.gov/of/2012/XXXX Process_Date: 2009-2010 Process_Step: Process_Description: Geophysical mapping Processing of the data was performed using Geosoft Oasis Montaj software package. Data were corrected for diurnal variations using the base station. Magnetometer was installed in a 2-m towed bird airfoil attached to the main tow line, 17.1 m below the helicopter Data were recorded at 10 Hz. Data were filtered to remove spikes and a lag correction of ~.1 s. Data were corrected for diurnal field variations and the International Geomagnetic Reference Field was removed using the flight date, and the altitude of the smoothed flown surface. Data are ordered according to line number. Metadata_Reference_Information: Metadata_Date: 20120711 Metadata_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Victoria Langenheim Contact_Organization: U.S. Geological Survey Contact_Position: geophysicist Contact_Address: Address_Type: mailing and physical address Address: 345 Middlefield Rd. City: Menlo Park State_or_Province: CA Postal_Code: 94025 Contact_Voice_Telephone: 650-329-5313 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