Identification_Information: Citation: Citation_Information: Originator: Ronald E. Sweeney Originator: Robert P. Kucks Originator: Patricia L. Hill Originator: Carol A. Finn Publication_Date: 2006 Title: Aeromagnetic Survey in Western Afghanistan: A Web Site for Distribution of Data Geospatial_Data_Presentation_Form: raster digital data Series_Information: Series_Name: U.S. Geological Survey Open-File Report Issue_Identification: Open-File Report 06-1325 Publication_Information: Publication_Place: Denver, Colorado, USA Publisher: U.S. Geological Survey Online_Linkage: http://pubs.usgs.gov/of/2006/1325 Description: Abstract: Aeromagnetic and related data were digitized from 1976 magnetic field and survey route location maps of western Afghanistan. The magnetic field data were digitized along contour lines from 33 maps in a series entitled "Map of Magnetic Field of Afghanistan (Western Area) Delta-Ta Isolines," compiled by V. A. Cnjagev and A. F. Bukhmastov. The survey route location data were digitized along flight-lines located on 33 maps in a series entitled "Survey Routes Location and Contours of Flight Equal Altitudes. Western Area of Afghanistan," compiled by Z. A. Alpatova, V. G. Kurnosov, and F. A. Grebneva. Purpose: Unknown. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 1976 Ending_Date: 1976 Currentness_Reference: survey dates Status: Progress: complete Maintenance_and_Update_Frequency: none planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: 60.8° E. longitude East_Bounding_Coordinate: 62.5° E. longitude North_Bounding_Coordinate: 35.3° N. latitude South_Bounding_Coordinate: 32.0° N. latitude Keywords: Place: Place_Keyword_Thesaurus: none Place_Keyword: Afghanistan Theme: Theme_Keyword_Thesaurus: none Theme_Keyword: geophysical data Theme_Keyword: aeromagnetic data Theme_Keyword: aeromagnetic grid Access_Constraints: none Use_Constraints: none Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Ronald Sweeney Contact_Organization: U.S. Geological Survey Contact_Address: Address_Type: mailing address Address: Box 25046, MS964 Denver Federal Center City: Denver State_or_Province: CO Postal_Code: 80225-0046 Country: USA Contact_Voice_Telephone: 303-236-1389 Contact_Electronic_Mail_Address: rsweeney@usgs.gov Native_Data_Set_Environment: These grids and databases were created using USGS processing programs on a UNIX system and on a PC using Geosoft/OASIS montaj application software. Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: The digital data are Geosoft databases and grids, which were created from the original digitized aeromagnetic data identified in this report. Data accuracies thus coincided with the original survey/data processing accuracies. The final aeromagnetic grid interval of 400 m was chosen as representative. The data in the original grids have been processed using formulas and methods that are not usually documented but that represent industry standard practices for airborne data reduction. Logical_Consistency_Report: Standard industry practices of the time were followed in data collection and processing. Completeness_Report: Areas with no data in the aeromagnetic grid are flagged with Geosoft dummy values. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: Horizontal position of the survey aircraft used to collect data being integrated into the composite grid were determined by varying standard aircraft navigation aids. Vertical_Positional_Accuracy: Vertical_Positional_Accuracy_Report: The individual aeromagnetic surveys that make up this data set were flown in draped mode at approximately 75-100 m above the terrain. Lineage: Process_Step: Process_Description: Unknown. Process_Date: 1976-2006 Process_Step: Process_Description: Each of the original aeromagnetic survey maps were digitized along coutour lines. The initial aeromagnetic grids for each survey were constructed using a minimum curvature algorithm and a grid cell size appropriate for the scale of the digitized map. The digitized aeromagnetic data for all surveys were then assembled and regridded to the final grid cell size of 400 m using a minimum curvature algorithm. Process_Date: 1976-2006 Entity_and_Attribute_Information: Overview_Description: Entity_and_Attribute_Overview: One aeromagnetic grid and database are included in this report: 34-66_mag.grd - Geosoft binary grid format Final western Afghanistan aeromagnetic anomaly grid from digitized data. 34-66_mag.gdb - Geosoft database format Final western Afghanistan aeromagnetic anomaly database from digitized data. The database above is also provided in the report in an additional format: Geosoft XYZ. (See the file "readme_RUS_datafiles.pdf" in this open-file report for details.) The grid projection specifications for the above grid and databases are provided in detail in this open-file report. Entity_and_Attribute_Detail_Citation: Open-File Report 06-1325 Detailed_Description: Entity_Type: Entity_Type_Label: gridded aeromagnetic Entity_Type_Definition: Ascii real number value Entity_Type_Definition_Source: well-established geophysical data quantities Attribute: Attribute_Label: Residual total intensity of Earth's magnetic field Attribute_Definition: Gridded values found in file '34-66_mag.grd' The total magnetic value minus a geomagnetic reference field, which is a long-wavelength regional magnetic field. The most commonly used reference field is calculated from the theoretical International Geomagnetic Reference Field (IGRF). The individual aeromagnetic survey data were digitized from original maps at original flight elevation surfaces. These digitized data were then combined and gridded at 400 m final grid cell size using a minimum curvature algorithm. Attribute_Definition_Source: see: Nettleton, L.L., 1971, Elementary Gravity and Magnetics for Geologists and Seismologists: Society of Exploration Geophysicists Monograph Series No. 1, p. 83-87. Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -989.355 Range_Domain_Maximum: 2363.940 Attribute_Units_of_Measure: nanoteslas Detailed_Description: Entity_Type: Entity_Type_Label: aeromagnetic anomaly database Entity_Type_Definition: Ascii real number value Entity_Type_Definition_Source: well-established geophysical data quantities Attribute: Attribute_Label: Residual total intensity of Earth's magnetic field Attribute_Definition: Aeromagnetic anomaly values found in file '34-66_mag.gdb' The total magnetic value minus a geomagnetic reference field, which is a long-wavelength regional magnetic field. The most commonly used reference field is calculated from the theoretical International Geomagnetic Reference Field (IGRF). Attribute_Definition_Source: see: Nettleton, L.L., 1971, Elementary Gravity and Magnetics for Geologists and Seismologists: Society of Exploration Geophysicists Monograph Series No. 1, p. 83-87. Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: -1680.0 Range_Domain_Maximum: 3335.0 Attribute_Units_of_Measure: nanoteslas Distribution_Information: Distributor: Contact_Information: Contact_Person_Primary: Contact_Person: Ron Sweeney Contact_Organization: U. S. Geological Survey Contact_Address: Address_Type: mailing address Address: Box 25046, MS 964 Denver Federal Center City: Denver State_or_Province: CO Postal_Code: 80225 Country: USA Contact_Voice_Telephone: 303-236-1389 Contact_Electronic_Mail_Address: rsweeney@usgs.gov Resource_Description: USGS Open-File Report 06-1325 Distribution_Liability: Although all data published in the grids and databases have been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials. Any use of trade, product, or firm 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: grd - gridded data files gdb - database files txt - ASCII description files Transfer_Size: 49.6 Mbytes is the largest file size Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: http://pubs.usgs.gov/of/2006/1325 Fees: no charge for online downloads Metadata_Reference_Information: Metadata_Date: 20060725 Metadata_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Ron Sweeney Contact_Organization: U.S. Geological Survey Contact_Address: Address_Type: mailing address Address: U.S. Geological Survey Box 25046 Mail Stop 964 Denver Federal Center City: Denver State_or_Province: CO Postal_Code: 80225 Country: USA Contact_Voice_Telephone: 303-236-1389 Contact_Electronic_Mail_Address: rsweeney@usgs.gov Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998