Identification_Information:
  Citation:
    Citation_Information:
          Originator: V.E. Langenheim
          Originator: J.T. Watt
          Originator: K.M. Denton
         Publication_Date: 2012
          Title: Magnetic map of the Irish Hills and surrounding areas, central California
          Geospatial_Data_Presentation_Form: point digital data
          Series_Information:
            Series_Name: Open-File Report
            Issue_Identification: 2012-1080
          Publication_Information:
            Publication_Place: Menlo Park, CA
            Publisher: U.S. Geological Survey
            Online Linkage: http://pubs.usgs.gov/of/2012/1080/
  Description:
    Abstract: Helicopter magnetic data and physical properties of Irish Hills and surrounding areas, central California
      Digital Files:  The database includes an ASCII file containing point magnetic data from the helicopter survey, two ASCII files with point locations of the local 
maximum horizontal gradient derived from the magnetic data, and one of physical property data.  This metadata file describes the point magnetic data.     
   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 New-Sense Geophysics Ltd. using Scintrex CS-3 Optically Pumped magnetometer for the airborne measurements and GEM System Overhauser GSM-19 magnetometer 
for the ground measurements. Lines were flown in a northeast-southwest direction and were spaced 150m apart. Northwest-southeast tie lines were also flown spaced 1500m apart. 
The survey was flown at a nominal 50-100m 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: -120.955000
      East_Bounding_Coordinate: -120.720000
      North_Bounding_Coordinate: 35.2872000
      South_Bounding_Coordinate: 35.1061000
  Keywords:
    Theme:
      Theme_Keyword: magnetics
      Theme_Keyword: magnetic anomaly
    Place:
      Place_Keyword: central California
      Place_Keyword: Irish Hills
  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:  2012-1080
      Publication_Information:
        Publication_Place:  Menlo Park, California
        Publisher:  U.S. Geological Survey
      Online_Linkage:  <URL:http://pubs.usgs.gov/ofr/2012/1080>

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: New-Sense Geophysics Ltd.
          Publication_Date: 2010
          Title: Logistics Report--Point Buchon Helimag 2009
          Geospatial_Data_Presentation_Form: vector digital data
      Type_of_Source_Media: disc
      Source_Citation_Abbreviation: New-Sense Geophysics Ltd.New-Sense Geophysics Ltd.New-Sense Geophysics Ltd.New-Sense Geophysics Ltd.New-Sense Geophysics Ltd. Report Helicopter Aeromagnetic 
Survey, Point Buchon, California, 2009
    Process_Step:
      Process_Description: Refer to Project Report by New-Sense Geophysics Ltd.
      Process_Date: 2010
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: helo_mag.xyz
    Attribute:
      Attribute_Label: Fiducial
      Attribute_Definition: fiducial count (flight specific)
      Attribute_Definition_Source: New-Sense Geophysics Ltd.
    Attribute:
      Attribute_Label: Line
      Attribute_Definition: line number
      Attribute_Definition_Source: New-Sense Geophysics Ltd.
    Attribute:
      Attribute_Label: Direction
      Attribute_Definition: direction of flight line
      Attribute_Definition_Source: New-Sense Geophysics Ltd.    
    Attribute:
      Attribute_Label: Date
      Attribute_Definition: date flown (YMMDD)
      Attribute_Definition_Source: New-Sense Geophysics Ltd.
    Attribute:
      Attribute_Label: julian
      Attribute_Definition: julian day (YYYYDDD)
      Attribute_Definition_Source: New-Sense Geophysics Ltd.
    Attribute:
      Attribute_Label: hr
      Attribute_Definition: hour flown (PST)
      Attribute_Definition_Source: New-Sense Geophysics Ltd.
    Attribute:
      Attribute_Label: min
      Attribute_Definition: minute flown (PST)
      Attribute_Definition_Source: New-Sense Geophysics Ltd.
    Attribute:
      Attribute_Label: sec
      Attribute_Definition: second flown (PST)
      Attribute_Definition_Source: New-Sense Geophysics Ltd.
    Attribute:
      Attribute_Label: lat_wgs84
      Attribute_Definition: latitude coordinate (WGS84 datum)
      Attribute_Definition_Source: New-Sense Geophysics Ltd.
      Attribute_Value_Accuracy_Information:
        Attribute_Value_Accuracy: 0.2 m
    Attribute:
      Attribute_Label: lon_wgs84
      Attribute_Definition: longitude coordinate (WGS84 datum)
      Attribute_Definition_Source: New-Sense Geophysics Ltd.
      Attribute_Value_Accuracy_Information:
        Attribute_Value_Accuracy: 0.2 m
    Attribute:
      Attribute_Label: utmx84
      Attribute_Definition: x UTM zone 10 coordinate
      Attribute_Definition_Source: New-Sense Geophysics Ltd.
      Attribute_Value_Accuracy_Information:
        Attribute_Value_Accuracy: 0.2 m
    Attribute:
      Attribute_Label: utmy84
      Attribute_Definition: y UTM zone 10 coordinate
      Attribute_Definition_Source: New-Sense Geophysics Ltd.
      Attribute_Value_Accuracy_Information:
        Attribute_Value_Accuracy: 0.2 m
    Attribute:
      Attribute_Label: utmx27
      Attribute_Definition: x UTM zone 10 coordinate (NAD27)
      Attribute_Definition_Source: New-Sense Geophysics Ltd.
      Attribute_Value_Accuracy_Information:
        Attribute_Value_Accuracy: 0.2 m
    Attribute:
      Attribute_Label: utmy27
      Attribute_Definition: y UTM zone 10 coordinate (NAD27)
      Attribute_Definition_Source: New-Sense Geophysics Ltd.
      Attribute_Value_Accuracy_Information:
        Attribute_Value_Accuracy: 0.2 m
    Attribute:
      Attribute_Label: gps_sec
      Attribute_Definition: GPS daily second counter (0-86399)
      Attribute_Definition_Source: New-Sense Geophysics Ltd.
    Attribute:
      Attribute_Label: gps_ht
      Attribute_Definition: Height above sea level
      Attribute_Definition_Source: New-Sense Geophysics 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: New-Sense Geophysics Ltd.
      Attribute_Value_Accuracy_Information:
        Attribute_Value_Accuracy: 1.5 m
    Attribute:
      Attribute_Label: m_base
      Attribute_Definition: measured base station magnetic field, located near Diablo Canyon
      Attribute_Definition_Source: New-Sense Geophysics Ltd.
      Attribute_Value_Accuracy_Information:
        Attribute_Value_Accuracy: 0.1 nT
    Attribute:
      Attribute_Label: x
      Attribute_Definition: Fluxgate x-axis (volts)
      Attribute_Definition_Source: New-Sense Geophysics Ltd.
      Attribute_Value_Accuracy_Information:
        Attribute_Value_Accuracy: 0.01 volt    
    Attribute:
      Attribute_Label: y
      Attribute_Definition: Fluxgate y-axis (volts)
      Attribute_Definition_Source: New-Sense Geophysics Ltd.
      Attribute_Value_Accuracy_Information:
        Attribute_Value_Accuracy: 0.01 volt    
    Attribute:
      Attribute_Label: z
      Attribute_Definition: Fluxgate z-axis (volts)
      Attribute_Definition_Source: New-Sense Geophysics Ltd.
      Attribute_Value_Accuracy_Information:
        Attribute_Value_Accuracy: 0.01 volt    
    Attribute:
      Attribute_Label: mag_raw
      Attribute_Definition: raw magnetic total field (uncompensated)
      Attribute_Definition_Source: New-Sense Geophysics Ltd.
      Attribute_Value_Accuracy_Information:
        Attribute_Value_Accuracy: 0.1 nT
     Attribute:
      Attribute_Label: mag_comp
      Attribute_Definition: compensated raw magnetic field
      Attribute_Definition_Source: New-Sense Geophysics Ltd.
      Attribute_Value_Accuracy_Information:
        Attribute_Value_Accuracy: 0.2 nT
    Attribute:
      Attribute_Label: mag_lag_cor
      Attribute_Definition: lag corrected mag-comp magnetic field
      Attribute_Definition_Source: New-Sense Geophysics Ltd.
      Attribute_Value_Accuracy_Information:
        Attribute_Value_Accuracy: 0.1 nT    
     Attribute:
      Attribute_Label: mag_diur_cor
      Attribute_Definition: diurnally-corrected mag_lag_comp magnetic field
      Attribute_Definition_Source: New-Sense Geophysics Ltd.
      Attribute_Value_Accuracy_Information:
        Attribute_Value_Accuracy: 0.1 nT    
     Attribute:
      Attribute_Label: head_corr
      Attribute_Definition: line to line heading correction
      Attribute_Definition_Source: New-Sense Geophysics Ltd.
      Attribute_Value_Accuracy_Information:
        Attribute_Value_Accuracy: 0.1 nT    
     Attribute:
      Attribute_Label: mag_head_cor
      Attribute_Definition: heading-corrected mag-diur-cor magnetic field
      Attribute_Definition_Source: New-Sense Geophysics Ltd.
      Attribute_Value_Accuracy_Information:
        Attribute_Value_Accuracy: 0.1 nT    
    Attribute:
      Attribute_Label: mag_sim_lvl
      Attribute_Definition: Conventionally leveled mag-head-cor
      Attribute_Definition_Source: New-Sense Geophysics Ltd.
      Attribute_Value_Accuracy_Information:
        Attribute_Value_Accuracy: 0.2 nT    
     Attribute:
      Attribute_Label: mag_mic_lvl
      Attribute_Definition: Microleveled mag-sim-lvl
      Attribute_Definition_Source: New-Sense Geophysics Ltd.
      Attribute_Value_Accuracy_Information:
        Attribute_Value_Accuracy: 0.2 nT    
    Attribute:
      Attribute_Label: igrf
      Attribute_Definition: Calculated IGRF model 2005 
      Attribute_Definition_Source: New-Sense Geophysics Ltd.
      Attribute_Value_Accuracy_Information:
        Attribute_Value_Accuracy: 0.1 nT     
     Attribute:
      Attribute_Label: mag_igrf_cor
      Attribute_Definition: IGRF corrected magnetic field (mag-mic-lvl)
      Attribute_Definition_Source: New-Sense Geophysics Ltd.s
      Attribute_Value_Accuracy_Information:
        Attribute_Value_Accuracy: 0.2 nT
    Attribute:
      Attribute_Label: tmi_final
      Attribute_Definition: IGRF corrected magnetic field (mag-igrf-cor)
      Attribute_Definition_Source: New-Sense Geophysics Ltd.
      Attribute_Value_Accuracy_Information:
        Attribute_Value_Accuracy: 0.2 nT
    Attribute:
      Attribute_Label: vdv
      Attribute_Definition: First order FFT2 vertical derivative (nT/m)
      Attribute_Definition_Source: New-Sense Geophysics Ltd.

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/2012/1080
  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 near Diablo Canyon.  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: 20120210
  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