Identification_Information: Citation: Citation_Information: Originator: V.E. Langenheim Originator: R.C. Jachens Publication_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 the Soda Lake 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 Firefly Aviation, Ltd. uusing Geometrics G-822A cesium magnetometer for the airborne measurements and GEM System Overhauser GSM-19 magnetometer for the base station measurements. Lines were flown in a northeast-southwest direction and were spaced 800m apart. Tie lines were also flown in a northwest-southeast direction spaced 8000 m apart. The survey was flown at a nominal 305m above topography. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 2009 Ending_Date: 2009 Currentness_Reference: publication date Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -116.783 East_Bounding_Coordinate: -115.994 North_Bounding_Coordinate: 35.6512 South_Bounding_Coordinate: 34.7044 Keywords: Theme: Theme_Keyword: magnetics Theme_Keyword: magnetic anomaly Place: Place_Keyword: southern California Place_Keyword: Mojave Desert Place_Keyword: Fort Irwin Place_Keyword: Soda 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 0.01 nT Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: GPS accuracy should be 1 meter Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: GPS accuracy should be 1 meter Lineage: Source_Information: Source_Citation: Source_Citation: Citation_Information: Originator: Firefly Aviation, Ltd. Publication_Date: 2009 Title: Final Survey Report High-Resolution Aeromagnetic Survey: Soda Lake, California, 2009 Geospatial_Data_Presentation_Form: vector digital data Type_of_Source_Media: disc Source_Citation_Abbreviation: Firefly Aviation, Ltd. Report Aeromagnetic Survey, Soda Lake Area, California, 2009 Process_Step: Process_Description: Refer to Project Report by Firefly Aviation, Ltd. Process_Date: 2009 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: 672778 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: 0.00001 Longitude_Resolution: 0.00001 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: sodalake_mag.xyz Attribute: Attribute_Label: Line Attribute_Definition: line number Attribute_Definition_Source: Firefly Aviation, Ltd. Attribute: Attribute_Label: lat Attribute_Definition: latitude coordinate (NAD27 datum) Attribute_Definition_Source: Firefly Aviation, Ltd. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 1 m Attribute: Attribute_Label: lon Attribute_Definition: longitude coordinate (NAD27 datum) Attribute_Definition_Source: Firefly Aviation, Ltd. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 1 m Attribute: Attribute_Label: date Attribute_Definition: year/month/day (YYYY/MM/DD) Attribute_Definition_Source: Firefly Aviation, Ltd. Attribute: Attribute_Label: galt Attribute_Definition: Height above sea level Attribute_Definition_Source: Firefly Aviation, Ltd. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.2 m Attribute: Attribute_Label: radarm Attribute_Definition: radar height (meters above ground level) Attribute_Definition_Source: Firefly Aviation, Ltd. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 1.5 m Attribute: Attribute_Label: barom Attribute_Definition: barometric altitude Attribute_Definition_Source: Firefly Aviation, Ltd. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 1.5 m Attribute_Label: rawmag Attribute_Definition: raw magnetic total field (uncompensated) Attribute_Definition_Source: Firefly Aviation, Ltd. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.1 nT Attribute: Attribute_Label: cmag Attribute_Definition: compensated raw magnetic field Attribute_Definition_Source: Firefly Aviation, Ltd. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.2 nT Attribute: Attribute_Label: maglag Attribute_Definition: lag corrected magdc magnetic field Attribute_Definition_Source: Firefly Aviation, Ltd. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.1 nT Attribute: Attribute_Label: diurnal Attribute_Definition: measured base station magnetic field, located at Barstow airport, CA Attribute_Definition_Source: Firefly Aviation, Ltd. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.1 nT Attribute: Attribute_Label: magdc Attribute_Definition: diurnally-corrected compensated magnetic field Attribute_Definition_Source: Firefly Aviation, Ltd. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.1 nT Attribute: Attribute_Label: maghdg Attribute_Definition: heading-corrected compensated magnetic field Attribute_Definition_Source: Firefly Aviation, Ltd. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.2 nT Attribute: Attribute_Label: tielev Attribute_Definition: preliminary leveled total field mag (tie lines only) Attribute_Definition_Source: Firefly Aviation, Ltd. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.2 nT Attribute: Attribute_Label: maglev Attribute_Definition: Preliminary leveled traverse lines (using tielev) Attribute_Definition_Source: Firefly Aviation, Ltd. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.2 nT Attribute: Attribute_Label: igrf Attribute_Definition: IGRF model 2005 calculated for actual time and elevation of data acquisition Attribute_Definition_Source: Firefly Aviation, Ltd. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.1 nT Attribute: Attribute_Label: magigrf Attribute_Definition: maglag minus igrf correction plus 54425 nT Attribute_Definition_Source: Firefly Aviation, Ltd.s Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.2 nT Attribute: Attribute_Label: magfinal Attribute_Definition: final tie-line leveled, decorrugated and microleveled magnetic field Attribute_Definition_Source: Firefly Aviation, Ltd. 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: 106385123 Network_Resource_Name: http://pubs.usgs.gov/of/2012/XXXX Process_Date: 2009-2010 Process_Step: Process_Description: Geophysical mapping Prior to data collection, Figure of Merit (FOM), altimeter calibration and lag tests were performed. Processing of the data was performed using Geosoft Oasis Montaj software package. Data were corrected for diurnal variations using the base station at the Ukiah airport. Compensation of the single tail sensor against aircraft and directional magnetic signals was applied real-time. Data were then leveled and the International Geomagnetic Reference Field was removed using the 2005 model, 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