Identification_Information: Citation: Citation_Information: Originator: V.E. Langenheim Publication_Date: 2015 Title: Aeromagnetic survey map of Sacramento Valley, California Geospatial_Data_Presentation_Form: point digital data Series_Information: Series_Name: Open-File Report Issue_Identification: 2015-1186 Publication_Information: Publication_Place: Menlo Park, CA Publisher: U.S. Geological Survey Online_Linkage: http://dx.doi.org/10.3133/ofr20151186 Description: Abstract: Aeromagnetic data for three surveys, magnetic gradients, and a grid of the detailed aeromagnetic data in the Sacramento Valley, California Digital Files: The database includes ASCII files containing point magnetic data from the Sacramento Delta, Red Bluff and Chico aeromagnetic surveys, a grid resulting from those survey data, and two ASCII files with point locations of the local maximum horizontal gradient derived from a residual magnetic grid. This metadata file describes the gridded magnetic values. Grid should be reprojected to UTM coordinates to get exact 200 m cell size. Purpose: Magnetic map identifies magnetic features as a basis for geophysical interpretations. Supplemental_Information: This database includes detailed aeromagnetic data flown by Goldak Airborne Surveys and Firefly Aviation Ltd. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 2011 Ending_Date: 2014 Currentness_Reference: publication date Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -123.1320 East_Bounding_Coordinate: -120.7304 North_Bounding_Coordinate: 40.81482 South_Bounding_Coordinate: 37.5513 Keywords: Theme: Theme_Keyword: magnetics Theme_Keyword: magnetic anomaly Theme_Keyword_Thesaurus: USGS Thesaurus Place: Place_Keyword: Sacramento Valley, California Place_Keyword: Sacramento Delta Place_Keyword: Red Bluff, California Place_Keyword: Chico, California Place_Keyword_Thesaurus: GNIS 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/stored and analyzed on 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: 2015-1186 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 nT Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: accuracy should be within 200 meters (grid cell size) Logical_Consistency_Report: see report Completeness_Report: see report Lineage: Process_Step: Process_Description: Data from detailed aeromagnetic surveys were interpolated to a rectangular grid with nodes spaced 200 m apart using a minimum curvature algorithm (Briggs, 1974) using a Transverse Mercator projection (central meridian -123.0; base latitude 0.0; scale factor 0.9996). To obtain same grid cell size, reproject locations given here to UTM projection. In the area where the northern part of the Chico survey overlaps with the Red Bluff survey, data from the Chico survey was retained because the Chico survey was flown closer to the nominal height above terrain. Holes in coverage were filled by interpolation. Process_Date: 2015 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: 787843 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: 0.001 Longitude_Resolution: 0.001 Geographic_Coordinate_Units: Decimal degrees Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1929 Ellipsoid_Name: Clarke 1866 Semi-major_Axis: 6378206 Denominator_of_Flattening_Ratio: 294.977 Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: mag_grid.xyz Entity_Type_Definition: ASCII Entity_Type_Definition_Source: Aeromagnetic gridded data Attribute: Attribute_Label: lon_nad27 Attribute_Definition: longitude coordinate Attribute_Definition_Source: this report Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 200 m Attribute: Attribute_Label: lat_nad27 Attribute_Definition: latitude coordinate Attribute_Definition_Source: this report Attribute_Value_Accuracy_Information: Attribute_Value_Accuracy: 200 m Attribute: Attribute_Label: magnetic_field Attribute_Definition: gridded magnetic field from detailed aeromagnetic data (nT) Attribute_Definition_Source: this report Distribution_Information: Distributor: Contact_Information: Contact_Person_Primary: Contact_Person: Victoria Langenheim Contact_Organization: U.S. Geological Survey Contact_Address: Address_Type: mailing address Address: 345 Middlefield Rd, MS 989 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 Resource_Description: Downloadable Data Distribution_Liability: This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards or with the North American Stratigraphic Code. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: ASCII Transfer_Size: 26800000 Network_Resource_Name: http://dx.doi.org/10.3133/ofr20151186 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_address: Network_resource_name: http://dx.doi.org/10.3133/ofr20151186 Fees: None Metadata_Reference_Information: Metadata_Date: 20150517 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