Citation:
Citation_Information:
Originator: U.S. Geological Survey
Originator: Coastal and Marine Geology Program
Publication_Date: 1989
Title:
Geophysical data for field activity 69002 (K-0-69-GM) in Bay of Campeche, Gulf of Mexico from 01/17/1969 to 01/29/1969
Geospatial_Data_Presentation_Form: tab-delimited ASCII text files
Publication_Information:
Publication_Place: Menlo Park, CA
Publisher: U.S. Geological Survey
Online_Linkage: http://www.ngdc.noaa.gov/mgg/trk/trackline/kane/ka939009/mgd77/
Larger_Work_Citation:
Citation_Information:
Originator: Wm. Clinton Steele
Originator: Carolyn H. Degnan
Originator: Gary B. Deeter
Originator: Jean A. Riordan
Publication_Date: 1980
Title:
DESCRIPTION OF MARINE GEOPHYSICAL DATA COLLECTED BY THE U.S. GEOLOGICAL SURVEY AND HOW TO OBTAIN IT
Edition: 1.0
Geospatial_Data_Presentation_Form: Digital Document
Series_Information:
Series_Name: U.S. Geological Survey Open File Report
Issue_Identification: 167
Publication_Information:
Publication_Place: Menlo Park, CA
Publisher: U.S. Geological Survey
Online_Linkage: http://pubs.usgs.gov/of/1989/0167/report.pdf
Description:
Abstract:
Single-beam bathymetry data along with transit satellite navigation data was collected as part of field activity 69002 (K-0-69-GM) in Gulf of Mexico from 01/17/1969 to 01/29/1969,
http://walrus.wr.usgs.gov/infobank/k/k069gm/html/k-0-69-gm.meta.html
These data are reformatted from space-delimited ASCII text files located in the Coastal and Marine Geology Program (CMGP) InfoBank field activity catalog at
http://walrus.wr.usgs.gov/infobank/k/k069gm/html/k-0-69-gm.bath.html into MGD77T format provided by the NOAA's National Geophysical Data Center(NGDC). The MGD77T format includes a header (documentation) file (.h77t) and a data file (.m77t). More information regarding this format can be found in the publication listed in the Cross_reference section of this metadata file.
These data and information are intended for science researchers,students, policy makers, and general public. These data are not to be used for navigation purposes. The data are reformatted into MGD77T standard format for inclusion into NOAA's NGDC geophysical database. From there the data will be made available to GeoMapApp (
http://www.geomapapp.org/ ) and Virtual Ocean (
http://www.virtualocean.org/ ) Earth-browsing software. Access to the data is also provided via the USGS Coastal and Marine Geoscience Data System (
http://cmgds.marine.usgs.gov/).
The navigation data are digitally collected using a Satellite Integrated Navigation (SINS) system. The system is a space-based satellite navigation maintained by the United States government and is accessible using a satellite receiver (MX706 SATNAV with Loran A). This system provides navigational accuracy of approximately 200 m.The Data Acquistion, Processing, and Storage (DAPS) group performs a number of processing steps to the navigation data once it is collected which can vary by cruise. These steps are outlined within the header information in each individual digital navigation (.05x) space-delimited ASCII data file. The header information rows are indicated by lines beginning with the character "!". There is no information on how the single-beam bathymetry, gravity, and magnetic data were collected. For each data gathering cruise leg, the available data in the following categories are forwarded to NGDC: navigation, gravity, magnetics, bathymetry, and seismic shot points. The available data for each cruise leg are re-formatted and combined into the Marine Geophysical Data Exchange Format (MGD77) and into the internal NGDC SEIS-NAV format by USGS using several USGS developed FORTRAN programs.The FORTRAN programs sample the navigation to every integer minute of the cruise. When necessary, the latitudes and longitudes are linearly interpo- lated. If the time between the actual navigation fixes exceeds five minutes, no data are included in the MGD77 file.To build the MGD77 file, gravity, magnetics, and bathymetry are added to this sampled navigation. When necessary, gravity, magnetics, and bathymetry data are linearly interpolated if the time between the actual data samples does not exceed five minutes. If a time gap exceeds this, the data are not reported.The navigation data are merged with the seismic shot point data in a SEIS- NAV format file. For this file, navigation data are interpolated for each shot point. Both types of files are written to magnetic tape and sent to NGDC.
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 19690117
Ending_Date: 19690129
Currentness_Reference: ground condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -96.36667
East_Bounding_Coordinate: -81.76666
North_Bounding_Coordinate: 28.38333
South_Bounding_Coordinate: 23.93333
Keywords:
Theme:
Theme_Keyword_Thesaurus: USGS Metadata Identifier
Theme_Keyword: USGS:63402ef1-254c-4bd0-b02e-3c70fa65756e
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: geoscientificinformation
Theme_Keyword: oceans
Theme:
Theme_Keyword_Thesaurus: None
Theme_Keyword: Marine Geology
Theme_Keyword: Marine Geophysics
Theme_Keyword: Single-beam Bathymetry
Theme_Keyword: Water Depth
Theme_Keyword: Seafloor Topography
Theme:
Theme_Keyword_Thesaurus: Data Categories for Marine Planning
Theme_Keyword: distributions
Theme_Keyword: bathymetry and elevation
Theme:
Theme_Keyword_Thesaurus: Marine Realms Information Bank (MRIB) keywords
Theme_Keyword: single-beam echo sounder
Theme_Keyword: marine geophysics
Theme:
Theme_Keyword_Thesaurus: USGS Thesaurus
Theme_Keyword: single-beam echo sounder
Theme_Keyword: bathymetry measurement
Theme_Keyword: bathymetry
Theme_Keyword: marine geophysics
Place:
Place_Keyword_Thesaurus: Geographic Names Information System (GNIS)
Place_Keyword: Gulf Coast
Place_Keyword: Gulf Coast, US
Place_Keyword: Gulf Mexico North
Place_Keyword: Gulf of Mexico
Place_Keyword: USA
Access_Constraints: None. These data are held in the public domain.
Use_Constraints:
This information is not intended for navigational purposes.Read and fully comprehend the metadata prior to data use. Uses of thesedata should not violate the spatial resolution of the data. Wherethese data are used in combination with other data of different resolution,the resolution of the combined output will be limited by the lowestresolution of all the data.Acknowledge the U.S. Geological Survey in products derived from these data.Share data products developed using these data with the U.S. GeologicalSurvey.
Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Gregory K. Miller
Contact_Organization: U.S. Geological Survey
Contact_Position: Physical Scientist
Contact_Address:
Address_Type: mailing and physical
Address: 600 4th Street South
City: St. Petersburg
State_or_Province: FL
Postal_Code: 33701
Country: USA
Contact_Voice_Telephone: (727) 803-8747, ext. 3020
Contact_Electronic_Mail_Address: gmiller@usgs.gov
Data_Set_Credit:
Louis Garrison (Chief Scientist, USGS Corpus Christi); Robert H. Fedden (Chief Scientist, NVO); Henry Berryhill (Scientist, USGS); Harry Hill (Scientist, USGS Western Region); Jack Lee (Scientist, USGS Western Region); Mike Marlow (Scientist, USGS Western Region); Bob Patrick (Scientist, USGS Western Region); Dave Scholl (Scientist, USGS Western Region); Dick Tagg (Scientist, USGS Western Region)
Cross_Reference:
Citation_Information:
Originator:
Hittelman, Allen M., Groman, Robert C., Haworth, Richard T., Holcombe, Troy L., McHendrie, Graig, Smith, Stuart M., and Metzger, Dan R.
Publication_Date: 2010
Title: The marine geophysical data exchange format - MGD77 / MGD77T
Publication_Information:
Publication_Place: Boulder, CO
Publisher:
National Geophysical Data Center, National Oceanic and Atmospheric Administration
Other_Citation_Details: 25 p.
Online_Linkage: http://www.ngdc.noaa.gov/mgg/dat/geodas/docs/mgd77.pdf
