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:  <URL:http://pubs.usgs.gov/of/2010/1070/>

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