Identification_Information: Citation: Citation_Information: Originator: V.E. Langenheim Originator: P.L. Hill Publication_Date: 2010 Title: Preliminary Aeromagnetic Map of Joshua Tree National Park and Vicinity, Southern California Geospatial_Data_Presentation_Form: point digital data Series_Information: Series_Name: Open-File Report Issue_Identification: 2010-1070 Publication_Information: Publication_Place: Menlo Park, CA Publisher: U.S. Geological Survey Online Linkage: http://pubs.usgs.gov/of/2010/1070/ Description: Abstract: New aeromagnetic data in aeromagnetic mosaic map of Joshua Tree National Park and vicinity, southern California Digital Files: The database includes two ASCII files containing new aeromagnetic data and two ASCII files with point locations of the local maximum horizontal gradient derived from the aeromagnetic data. This metadata file describes the new aeromagnetic data. Purpose: Aeromagnetic 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 EON Geosciences, Inc. using Geometrics G-822A cesium magnetometer for the airborne measurements and GEM System Overhauser GSM-19 magnetometer for the ground measurements. Lines were flown in a north-south direction and were spaced 800m apart. East-west tie lines were also flown spaced 8000 m apart. The survey was flown at a nominal 305m above topography and flown in two blocks A and B. A is the northern block; the northwest corner of block B nearly touches the southeast corner of block A. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 2008 Ending_Date: 2008 Currentness_Reference: publication date Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -116.50 East_Bounding_Coordinate: -115.25 North_Bounding_Coordinate: 34.17 South_Bounding_Coordinate: 33.61 Keywords: Theme: Theme_Keyword: magnetics Theme_Keyword: magnetic anomaly Place: Place_Keyword: Southern California Place_Keyword: Eastern Transverse Ranges Place_Keyword: Joshua Tree National Park 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 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: 2010-1070 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 within 1 meter Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: GPS accuracy should be within 1 meter Lineage: Source_Information: Source_Citation: Citation_Information: Originator: EON Geosciences, Inc. Publication_Date: 2008 Title: Final Survey Report High-Resolution Aeromagnetic Survey: Joshua Tree, California, 2008 Geospatial_Data_Presentation_Form: vector digital data Type_of_Source_Media: disc Source_Citation_Abbreviation: EON Geosciences, Inc., Project Report Aeromagnetic Survey, Joshua Tree, California, 2008 Process_Step: Process_Description: Refer to Project Report by EON Geosciences, Inc. Process_Date: 2008 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: 345511 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: joshua_tree_mag_blocka.xyz Attribute: Attribute_Label: Line Attribute_Definition: line number Attribute_Definition_Source: EON Geosciences, Inc. Attribute: Attribute_Label: Direction Attribute_Definition: line direction (angle clockwise relative to north) Attribute_Definition_Source: EON Geosciences, Inc. Attribute: Attribute_Label: lon_nad27 Attribute_Definition: longitude coordinate Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.2 m Attribute: Attribute_Label: lat_nad27 Attribute_Definition: latitude coordinate Attribute_Definition_Source: EON Geosciences, Inc Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.2 m Attribute: Attribute_Label: X_wgs84 Attribute_Definition: x UTM zone 10 coordinate Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.2 m Attribute: Attribute_Label: Y_wgs84 Attribute_Definition: y UTM zone 10 coordinate Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.2 m Attribute: Attribute_Label: X_nad27 Attribute_Definition: x UTM zone 10 coordinate Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.2 m Attribute: Attribute_Label: Y_nad27 Attribute_Definition: y UTM zone 10 coordinate Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.2 m Attribute: Attribute_Label: fid10 Attribute_Definition: fiducial time - seconds after midnight UTC Attribute_Definition_Source: EON Geosciences, Inc. Attribute: Attribute_Label: date Attribute_Definition: year and julian date (YY/DDD) (UTC) Attribute_Definition_Source: EON Geosciences, Inc. Attribute: Attribute_Label: tgps Attribute_Definition: hour, minutes, seconds (HH:MM:SS) Attribute_Definition_Source: EON Geosciences, Inc. Attribute: Attribute_Label: raltlc Attribute_Definition: radar altimeter (meters above ground level) Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 1.5 m Attribute: Attribute_Label: baltlc Attribute_Definition: barometric altimeter (mean sea level) Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 1.5 m Attribute: Attribute_Label: z Attribute_Definition: DGPS altitude (mean sea level) Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.2 m Attribute: Attribute_Label: baseA Attribute_Definition: IGRF corrected ground base station located in Bermuda Dunes, CA Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.1 nT Attribute: Attribute_Label: um31 Attribute_Definition: raw magnetic total field (uncompensated) Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.1 nT Attribute: Attribute_Label: mag_lev Attribute_Definition: tie line leveled total field mag Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.2 nT Attribute: Attribute_Label: magigrf Attribute_Definition: final levelled residual mag Attribute_Definition_Source: EON Geosciences, Inc.s Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.3 nT Attribute: Attribute_Label: m31 Attribute_Definition: compensated raw mag Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.1 nT Attribute: Attribute_Label: maglc Attribute_Definition: edited total field mag, de-spike and filter applied on m31 Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.1 nT Attribute: Attribute_Label: maglcb Attribute_Definition: diurnal corrected TFM Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.1 nT Attribute: Attribute_Label: igrf Attribute_Definition: IGRF value calculated with draped z Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.1 nT Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: joshua_tree_mag_blockb.xyz Attribute: Attribute_Label: Line Attribute_Definition: line number Attribute_Definition_Source: EON Geosciences, Inc. Attribute: Attribute_Label: Direction Attribute_Definition: line direction (angle clockwise relative to north) Attribute_Definition_Source: EON Geosciences, Inc. Attribute: Attribute_Label: lon_nad27 Attribute_Definition: longitude coordinate Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.2 m Attribute: Attribute_Label: lat_nad27 Attribute_Definition: latitude coordinate Attribute_Definition_Source: EON Geosciences, Inc Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.2 m Attribute: Attribute_Label: X_wgs84 Attribute_Definition: x UTM zone 10 coordinate Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.2 m Attribute: Attribute_Label: Y_wgs84 Attribute_Definition: y UTM zone 10 coordinate Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.2 m Attribute: Attribute_Label: X_nad27 Attribute_Definition: x UTM zone 10 coordinate Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.2 m Attribute: Attribute_Label: Y_nad27 Attribute_Definition: y UTM zone 10 coordinate Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.2 m Attribute: Attribute_Label: fid10 Attribute_Definition: fiducial time - seconds after midnight UTC Attribute_Definition_Source: EON Geosciences, Inc. Attribute: Attribute_Label: date Attribute_Definition: year and julian date (YY/DDD) (UTC) Attribute_Definition_Source: EON Geosciences, Inc. Attribute: Attribute_Label: tgps Attribute_Definition: hour, minutes, seconds (HH:MM:SS) Attribute_Definition_Source: EON Geosciences, Inc. Attribute: Attribute_Label: raltlc Attribute_Definition: radar altimeter (meters above ground level) Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 1.5 m Attribute: Attribute_Label: baltlc Attribute_Definition: barometric altimeter (mean sea level) Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 1.5 m Attribute: Attribute_Label: z Attribute_Definition: DGPS altitude (mean sea level) Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.2 m Attribute: Attribute_Label: baseA Attribute_Definition: IGRF corrected ground base station located in Bermuda Dunes, CA Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.1 nT Attribute: Attribute_Label: um31 Attribute_Definition: raw magnetic total field (uncompensated) Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.1 nT Attribute: Attribute_Label: mag_lev Attribute_Definition: tie line leveled total field mag Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.2 nT Attribute: Attribute_Label: magigrf Attribute_Definition: final levelled residual mag Attribute_Definition_Source: EON Geosciences, Inc.s Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.3 nT Attribute: Attribute_Label: m31 Attribute_Definition: compensated raw mag Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.1 nT Attribute: Attribute_Label: maglc Attribute_Definition: edited total field mag, de-spike and filter applied on m31 Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.1 nT Attribute: Attribute_Label: maglcb Attribute_Definition: diurnal corrected TFM Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.1 nT Attribute: Attribute_Label: igrf Attribute_Definition: IGRF value calculated with draped z Attribute_Definition_Source: EON Geosciences, Inc. Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 0.1 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: 78748040 Network_Resource_Name: http://pubs.usgs.gov/of/2010/1070/ Process_Date: 2007-2010 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 Bermuda Dunes (note that the base station values are not provided for lines 1050 and 1070 because the base station did not record--values were adjusted using tie lines) after data were edited for spikes. 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: 20100430 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