Identification_Information:
Citation:
Citation_Information:
Originator:
U.S. Geological Survey, Department of Interior and the
National Geophysical Data Center, NOAA
Publication_Date: 2001
Title: Newberry, Oregon
Geospatial_Data_Presentation_Form: tabular digital data
Larger_Work_Citation:
Citation_Information:
Originator:
U.S. Geological Survey, Department of the Interior, and the
National Geophysical Data Center
Publication_Date: 2001
Title:
Digital flight-line aeromagnetic data sets of the
Conterminous United States, Hawaii, and Puerto Rico
Series_Information:
Series_Name: U.S. Geological Survey Open-File Report
Issue_Identification: OFR 02-361
Publication_Information:
Publication_Place: Denver, CO
Publisher: U.S. Geological Survey
Description:
Abstract:
Aeromagnetic data were collected along flight lines by instruments in an
aircraft that recorded magnetic-field values and locations. This dataset
presents latitude, longitude, altitude, and magnetic-field values.
Purpose:
Aeromagnetic surveys are used for geophysical prospecting. Some
variations in magnetic measurements are caused by rocks that
contain significant amounts of magnetic minerals (magnetite being
the most common). These anomalies reflect variations in the
amount and type of magnetic material and the shape and depth of
the body of rock.
Aeromagnetic anomaly maps are important tools in mapping
surficial and buried igneous rocks. The features and patterns
of aeromagnetic anomalies can also be used to delineate details
of subsurface geology including the locations of buried faults and
the thickness of surficial sedimentary rocks.
Supplemental_Information:
The U.S. Geological Survey has contracted or flown numerous
airborne surveys over a long period (1950's to present). Not
all flight-line data have been released to the public
because of lack of personnel to reformat data and service the
requests. With the improvement in digital communication
and the ability to store and transmit large data sets, the
USGS is now able to release the flight-line data in a
common format.
A companion CD-ROM/web site has been released containing
magnetic data that were generated by digitizing analog maps.
Digital flight-line data used to create the analog maps are
unavailable. Reference is in the Cross-Reference section of
this metadata file.
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 197503
Ending_Date: 197504
Currentness_Reference:
Time period indicates dates of airborne survey
data collection. Time period is expressed in the
format YYYYMM or YYYYMMDD when further accuracy is available.
Status:
Progress: complete
Maintenance_and_Update_Frequency: none planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -121.53
East_Bounding_Coordinate: -121.00
North_Bounding_Coordinate: 43.85
South_Bounding_Coordinate: 43.50
Data_Set_G-Polygon:
Data_Set_G-Polygon_Outer_G-Ring:
G-Ring:
-121.43 43.85, -121.00 43.85, -121.00 43.50,
-121.53 43.50, -121.43 43.85
Keywords:
Theme:
Theme_Keyword_Thesaurus: none
Theme_Keyword: geophysical surveys
Theme_Keyword: aeromagnetic data
Theme_Keyword: airborne surveys
Theme_Keyword: magnetic surveys
Theme_Keyword: residual magnetic field
Theme_Keyword: total field
Theme_Keyword: magnetic
Place:
Place_Keyword_Thesaurus: none
Place_Keyword: United States
Place_Keyword: Oregon
Place_Keyword: OR
Place_Keyword: Newberry
Access_Constraints: none
Use_Constraints:
none. Acknowledgement of the U.S. Geological Survey and the
National Geophysical Data Center would be appreciated
in products derived from these data.
Point_of_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: USGS Gravity and Magnetics Contact
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
Contact_Voice_Telephone: 303-236-1343
Contact_Electronic_Mail_Address: grav_mag@usgs.gov
Browse_Graphic:
Browse_Graphic_File_Name:
http://pubs.usgs.gov/ofr/2002/ofr-02-361
Browse_Graphic_File_Description:
An image of the flight lines showing total magnetic intensity
along the flight lines.
Browse_Graphic_File_Type: JPEG
Data_Set_Credit:
These USGS employees contributed to reformatting and archiving these data:
Viki Bankey, Carol Finn, Pat Hill, Holly Hindle,
Bob Kucks, Vicki Rystrom, Sarah Shearer
Cooperating contributors from the National Geophysical Data Center are:
Ronald Buhmann, David Dater, Susan McLean,
Stewart Racey
Native_Data_Set_Environment:
These data were originally recorded on 9-track
magnetic tapes and were transferred to CD-ROM.
Data processing took place on an HP workstation
running a Windows NT operating system. Data
were reformatted using the Geosoft, Inc., program
Oasis Montaj version 4.3.
Cross_Reference:
Citation_Information:
Originator: U.S. Geological Survey
Publication_Date: 1999
Title:
Digitized Aeromagnetic Datasets of the Conterminous United States,
Hawaii, and Puerto Rico
Geospatial_Data_Presentation_Form: raster digital data
Series_Information:
Series_Name: U.S. Geological Survey Open-File Report
Issue_Identification: OFR 99-557
Publication_Information:
Publication_Place: Denver CO
Publisher: U.S. Geological Survey
Other_Citation_Details:
CD-ROM or online files
Complements this publication with analog data
Online_Linkage:
http://greenwood.cr.usgs.gov/pub/open-file-reports/ofr-99-0557
Cross_Reference:
Citation_Information:
Originator: U.S. Geological Survey
Publication_Date: 1979
Title:
Aeromagnetic map of the Newberry area, Oregon,
79-1366
Geospatial_Data_Presentation_Form: map
Series_Information:
Series_Name: U.S. Geological Survey Open-File Report
Issue_Identification: OFR 79-1366
Publication_Information:
Publication_Place: Denver, CO
Publisher: U.S. Geological Survey
Other_Citation_Details: map scale 1:62,500
Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
The data in this file have been processed using various formulas and
methods that are not usually documented but that represent
industry standard practices for airborne data reduction. For example,
position is listed as latitude and longitude, but these values
were derived from the raw navigation data depending on the system used.
(see notes under horizontal accuracy). Line numbers were added to
records, and unusable data at flight-line ends were discarded
(as aircraft slowed and turned around). Separate recordings were
correlated by time and assigned to the correct location.
The exact accuracies of these processing steps may not be known.
They are discussed in the sections on attribute or positional
accuracies.
Logical_Consistency_Report:
The data in this file were collected by a single contractor or group
who were responsible for collecting and processing the data.
The data from this survey were collected using the same instruments
(magnetometers, altimeters, navigational systems) throughout
the survey and were collected in a normal length of time with no long
delays between survey beginning and end.
Survey contracts specified the conditions and specifications under which
these data were collected. Standard industry practices of the time
were followed in data collection and processing.
Completeness_Report:
Loss of data due to poor transmission, channel dropout, obvious spiking,
missing channels, and other obvious errors were replaced with the
value -9999.9, such as in the radar, barom, and totmag channels.
The contractor database did not have flight line direction (directn),
year (year), day (jul_day), fiducial (fiducial), radar altimeter (radar),
barometric altimeter (barom), or residual magnetics (resmag) channels. A
dummy value of -1 was used in the directn channel in order to conform with
the established template. The values in the fiducial channel were
generated using Oasis Montaj referencing values in the latitude channel.
There are no tie lines for this survey.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
Flight Path Recovery
Horizontal position of the survey aircraft used to collect
data were determined by reconciling down-looking photographs
(recorded on continuous-strip film) with topographic maps
and orthophotoquadrangle maps. Fiducial numbers and marks,
impressed on any paper strips that were recording data or
added to magnetic tape records, were included
as a function of time to further reconcile location with
instrumentation.
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report:
The aircraft vertical position was determined using the
navigational positioning equipment on the aircraft, which
were radar altimeter and barometric altimeter.
Radar altimeters are estimated to have an error
of 2-5% of the altitude (Richard Hansen, PRJ, Inc.,
written communication).
Barometric altimeters are quite accurate, but are
typically operated in an uncorrected mode. The
diurnal variation in air pressure over the course of
a flight can produce a 50-100 ft error in the
barometric altimeter reading. In addition, pressure microcells
create short-period air pressure changes equivalent
to about 10 ft under typical conditions (Richard
Hansen, PRJ, Inc., written communication)
This data set was collected at a fixed barometric altitude
of 8000 ft.
Lineage:
Process_Step:
Process_Description:
Conversion of measured values to geographic position and
magnetic values was performed by the contractor using
industry standard practices.
Details are found under Attribute Accuracy Report,
Horizontal_Position_Accuracy_Report, and
Vertical_Position_Accuracy_Report
Unless noted, conversion processes were not reported to the USGS.
Unpublished products generated by the contractor included magnetic
tapes, a map of residual or total field magnetics, and perhaps some
written documentation.
Process_Date: 1975
Process_Step:
Process_Description:
USGS reformatting of contractor data to standard format.
USGS personnel used the software package Oasis Montaj version 4.3 by
Geosoft, Inc., to read in the original contractor's data.
Latitude, longitude, altitude, and magnetic values were
checked for obvious errors or spikes and values of -9999.9
were given where the value could not be reasonably corrected.
Other errors in the data were not corrected. Horizontal positions
were converted to latitude and longitude if the original values
were UTM meters. Elevations were converted from meters to feet
(1 m = 3.2808 ft). Information was added that was missing from the
data file but was recorded elsewhere. The reformatted data file was
written in the format described in the section on
Entity_and_Attribute_Overview.
Process_Date: 200212
Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: point
Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Geographic:
Latitude_Resolution: .0001
Longitude_Resolution: .0001
Geographic_Coordinate_Units: decimal degrees
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1927
Ellipsoid_Name: Clarke 1866
Semi-major_Axis: 6,378,206.4
Denominator_of_Flattening_Ratio: 294.98
Vertical_Coordinate_System_Definition:
Altitude_System_Definition:
Altitude_Datum_Name: National Geodetic Vertical Datum of 1929
Altitude_Resolution: 1
Altitude_Distance_Units: feet
Altitude_Encoding_Method:
Explicit elevation coordinate included
with horizontal coordinates
Entity_and_Attribute_Information:
Overview_Description:
Entity_and_Attribute_Overview:
Airborne survey specifications
These items are constant for the entire survey
Project number: 3066
Project name: Newberry, Oregon
Survey flown by: Aerial Surveys, Ltd.
Survey flown for: U.S. Geological Survey
Approx. no. of line miles: 825
Survey height: 8000 ft
Altitude method: Constant barometric elevation
Flight-line spacing: 0.5 to 1.0 mi
Flight-line direction: E-W
Aircraft used: unknown
Airport - arrival: unknown
Airport - departure: unknown
Magnetometer used: unknown
Sensor tow distance: unknown
Entity_and_Attribute_Detail_Citation:
Nettleton, L.L., 1971, Elementary Gravity and Magnetics for
Geologists and Seismologists: Society of Exploration Geophysicists
Monograph Series No. 1, p. 83-87.
Dobrin, M.B., 1976, Introduction to Geophysical
Prospecting: New York, McGraw-Hill Book Company,
p. 505-517.
Overview_Description:
Entity_and_Attribute_Overview:
Each record contains the following 11 attributes:
No abbrev.name contents
1 line_no flight line number
2 directn flight line direction, azimuth degrees from north
(integer)
3 longitud longitude (decimal degrees)
4 latitude latitude (decimal degrees)
5 year year flown (integer)
6 jul_day Julian day flown (integer)
7 fiducial fiducial number (integer)
8 radar radar altimeter reading above ground (feet)
9 barom altitude above mean sea level (feet)
10 totmag corrected magnetic value (nT)
11 resmag residual magnetic value (nT)
Entity_and_Attribute_Detail_Citation:
Nettleton, L.L., 1971, Elementary Gravity and Magnetics for
Geologists and Seismologists: Society of Exploration Geophysicists
Monograph Series No. 1, p. 83-87.
Dobrin, M.B., 1976, Introduction to Geophysical
Prospecting: New York, McGraw-Hill Book Company,
p. 505-517.
Detailed_Description:
Entity_Type:
Entity_Type_Label: record for one magnetic data point
Entity_Type_Definition:
The set of all measurements reported for a magnetic data point
having the same spatial location.
Entity_Type_Definition_Source:
Standard aeromagnetic data collection procedures as written in
the contract for survey collection.
Attribute:
Attribute_Label: line_no
Attribute_Definition: flight line number
Attribute_Definition_Source: often assigned by airborne survey crew
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 37
Range_Domain_Maximum: 71
Attribute_Units_of_Measure: alphanumeric value
Attribute:
Attribute_Label: directn
Attribute_Definition:
direction of flight line, azimuth degrees
clockwise from north
Attribute_Definition_Source: self evident
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -1
Range_Domain_Maximum: -1
Attribute_Units_of_Measure: degrees
Attribute:
Attribute_Label: longitud
Attribute_Definition: longitude - geographic coordinate
Attribute_Definition_Source: self evident
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -121.7079
Range_Domain_Maximum: -120.9258
Attribute_Units_of_Measure: decimal degrees
Attribute:
Attribute_Label: latitude
Attribute_Definition: latitude - geographic coordinate
Attribute_Definition_Source: self evident
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 43.4842
Range_Domain_Maximum: 43.8785
Attribute_Units_of_Measure: decimal degrees
Attribute:
Attribute_Label: year
Attribute_Definition: year of data point collection
Attribute_Definition_Source: self evident
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 1975
Range_Domain_Maximum: 1975
Attribute:
Attribute_Label: jul_day
Attribute_Definition:
Julian day, where Jan. 1 = 1 and
Dec. 31 = 365 or 366 (leap year)
Attribute_Definition_Source: self evident
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 60
Range_Domain_Maximum: 60
Attribute_Value_Accuracy_Information:
Attribute_Value_Accuracy: 31
Attribute_Value_Accuracy_Explanation:
The date assigned was the first of March, 1975 based on
the contractor report and personnel experience.
Attribute:
Attribute_Label: fiducial
Attribute_Definition:
A fiducial number is a mark which indicates points of
simultaneity. It is a user-defined integer used during
airborne operations to correlate recording devices (magnetometers)
with navigational records (altimeters, camera film, strip charts)
that were recorded at the same time.
Attribute_Definition_Source:
Sheriff, R.E., 1984, Encyclopedic dictionary of
exploration geophysics: Tulsa, OK, Society of
Exploration Geophysicists, p. 89.
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0
Range_Domain_Maximum: 18631
Attribute:
Attribute_Label: radar
Attribute_Definition:
radar altimetry reading, in feet
An aircraft navigational system in which short electromagnetic waves
are transmitted, and the energy scattered back by reflection
is detected. From this measurement, the distance between the aircraft
and the ground is calculated and recorded as radar altimetry.
Values of -9999.9 indicate missing data.
Attribute_Definition_Source:
Sheriff, R.E., 1984, Encyclopedic dictionary of exploration geophysics:
Tulsa, OK, Society of Exploration Geophysicists, p. 89.
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -9999.9
Range_Domain_Maximum: -9999.9
Attribute_Units_of_Measure: feet
Attribute:
Attribute_Label: barom
Attribute_Definition:
altitude above mean sea level, in feet, measured using the
barometer that is part of the aircraft navigation system
Values of -9999.9 indicate missing data.
Attribute_Definition_Source: self evident
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -9999.9
Range_Domain_Maximum: -9999.9
Attribute_Units_of_Measure: feet
Attribute:
Attribute_Label: totmag
Attribute_Definition:
Raw magnetic value with base magnetometer corrections applied.
Because the magnetic field of the earth varies diurnally,
a stationary base magnetometer is maintained on the ground
during airborne surveying. The base magnetometer records
changes in the magnetic field (in nanoTeslas) as a function
of time. The magnetic changes may have an amplitude of 20
to 50 nanoTeslas. If changes are more severe, as would
occur from a magnetic storm, surveying is discontinued or
the data recorded are not used.
Diurnal variations are then removed from the airborne magnetic
data based on the common time.
Values of -9999.9 indicate missing data.
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.
A description of magnetometers and how they measure
the total magnetic field can be found in:
Dobrin, M.B., 1976, Introduction to Geophysical
Prospecting: New York, McGraw-Hill Book Company,
p. 505-517.
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 53975
Range_Domain_Maximum: 55586
Attribute_Units_of_Measure: nanoTeslas
Attribute_Value_Accuracy_Information:
Attribute_Value_Accuracy: 2
Attribute_Value_Accuracy_Explanation:
The airborne magnetometer is accurate to about 1 nanoTesla,
and the base magnetometer has the same accuracy. The accuracy
of the base-corrected airborne value therefore is near 2 nanoTeslas
or better.
Attribute_Measurement_Frequency:
The magnetometer has a recharging interval of 0.5
seconds. The data were recorded at unknown intervals.
Attribute:
Attribute_Label: resmag
Attribute_Definition:
residual magnetic value
The total magnetic value minus a geomagnetic reference
field (GRF), which is a long wavelength regional magnetic
field. A series of models of the earth's magnetic field
were created from the use of three Polar Orbiting Geophysical
Observatories (POGO) collected at Goddard Space Flight
Center. OGO 2, 4, and 6 collected scalar intensity
measurements between October 1965 and May 1968. POGO models
offered the earliest and perhaps best coverage of the whole
earth, derived from a single source. Each model corresponds
to a specific time span within the 1965-1968 period. The
appropriate model to remove from the survey data depends on
the year of survey acquisition.
For this survey, the field removed was the POGO updated to
April 1975.
Values of -9999.9 indicate missing data.
Attribute_Definition_Source:
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: -9999.9
Range_Domain_Maximum: -9999.9
Attribute_Units_of_Measure: nanoTeslas
Attribute_Value_Accuracy_Information:
Attribute_Value_Accuracy: 2
Attribute_Value_Accuracy_Explanation:
The Geomagnetic Reference Field that was subtracted from
the total magnetic value is based on a model, which was
updated to the date of the survey. New models are
available at five year intervals. These models have
varying degrees of accuracy in determining the local
reference field.
Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: CD-ROM distributor: USGS Information Services
Contact_Address:
Address_Type: mailing address
Address:
Box 25286, Building 810
Denver Federal Center
City: Denver
State_or_Province: CO
Postal_Code: 80225
Contact_Voice_Telephone:
303-202-4700
or 1-888-ASK-USGS
Contact_Electronic_Mail_Address: www.usgs.gov/pubprod
Resource_Description: USGS Open-File Report OFR 02-361
Distribution_Liability:
Although all data published on this CD-ROM 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: ASCII
Format_Information_Content:
Each line contains data in the following format,
beginning with line 1(no header included):
line_no I5
directn I4
longitud F11.4
latitude F9.4
year I5
jul_day I4
fiducial I7
radar F8.1
barom F8.1
totmag F9.2
resmag F9.2, 1X
File_Decompression_Technique: gunzip
Digital_Transfer_Option:
Offline_Option:
Offline_Media: CD-ROM
Recording_Format: ISO 9660
Fees:
CD-ROM prices are subject to change. Please call or see
http://mapping.usgs.gov/esic/prices/
Ordering_Instructions:
Detailed instructions can be found at
www.usgs.gov/pubprod
Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:
Web site administration: U.S Geological Survey
Central Publications Group
Contact_Address:
Address_Type: mailing address
Address:
Central Publications Group
USGS MS 902, Box 25046 DFC
City: Denver
State_or_Province: CO
Postal_Code: 80225-0046
Contact_Voice_Telephone: 303-236-5486
Resource_Description: USGS Open-File Report OFR 02-361
Distribution_Liability:
Although all data published on this CD-ROM 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: ASCII
Format_Specification:
Each line contains data in the following format,
beginning with line 1 (no header included):
line_no I5
directn I4
longitud F11.4
latitude F9.4
year I5
jul_day I4
fiducial I7
radar F8.1
barom F8.1
totmag F9.2
resmag F9.2, 1X
File_Decompression_Technique: gunzip
Format_Version_Number: 4.1
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name:
ftp://greenwood.cr.usgs.gov/pub/open-file-reports/ofr-02-361
Online_Computer_and_Operating_System:
Hewlett Packard 9000/K220
UNIX server running HPUX 11.00
Fees: none
Metadata_Reference_Information:
Metadata_Date: 20021217
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: USGS Gravity and Magnetics contact
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: 80225-0046
Contact_Voice_Telephone: 303-236-1343
Contact_Electronic_Mail_Address: grav_mag@usgs.gov
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial
Metadata
Metadata_Standard_Version: FGDC-STD-001-1998