l1282wg.m77t - MGD77 data file for Geophysical data from field activity L-12-82-WG in Western Gulf of Alaska from 09/22/1982 to 10/05/1982

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Frequently anticipated questions:


What does this data set describe?

Title:
l1282wg.m77t - MGD77 data file for Geophysical data from field activity L-12-82-WG in Western Gulf of Alaska from 09/22/1982 to 10/05/1982
Abstract:
Single-beam bathymetry, gravity, and magnetic data along with DGPS navigation data was collected as part of field activity L-12-82-WG in Western Gulf of Alaska from 09/22/1982 to 10/05/1982, http://walrus.wr.usgs.gov/infobank/l/l1282wg/html/l-12-82-wg.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/l/l1282wg/html/l-12-82-wg.bath.html, http://walrus.wr.usgs.gov/infobank/l/l1282wg/html/l-12-82-wg.grav.html, and http://walrus.wr.usgs.gov/infobank/l/l1282wg/html/l-12-82-wg.mag.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.
Supplemental_Information:
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. 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 interpolated. 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.
  1. How might this data set be cited?
    U.S. Geological Survey, and Coastal and Marine Geology Program, 2013, l1282wg.m77t - MGD77 data file for Geophysical data from field activity L-12-82-WG in Western Gulf of Alaska from 09/22/1982 to 10/05/1982: U.S. Geological Survey, Menlo Park, CA.

    Online Links:

    This is part of the following larger work.

    Steele, Wm. Clinton, Degnan, Carolyn H., Deeter, Gary B., and Riordan, Jean A., 1980, DESCRIPTION OF MARINE GEOPHYSICAL DATA COLLECTED BY THE U.S. GEOLOGICAL SURVEY AND HOW TO OBTAIN IT: U.S. Geological Survey Open File Report 167, U.S. Geological Survey, Menlo Park, CA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -166.52713
    East_Bounding_Coordinate: -158.30482
    North_Bounding_Coordinate: 55.33219
    South_Bounding_Coordinate: 52.53880
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 22-Sep-1982
    Ending_Date: 05-Oct-1982
    Currentness_Reference:
    ground condition
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: tab-delimited ASCII text files
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      Indirect_Spatial_Reference: Western Gulf of Alaska
      This is a Point data set. It contains the following vector data types (SDTS terminology):
      • Point
    2. What coordinate system is used to represent geographic features?
      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000001. Longitudes are given to the nearest 0.000001. Latitude and longitude values are specified in Decimal degrees. The horizontal datum used is D_WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.25722210100002.
  7. How does the data set describe geographic features?
    l1282wg.m77t
    MGD77T single-beam bathymetry data file for L1282WG (Source: NOAA's National Geophysical Data Center, See Hittelman and others (2010) Cross_Reference section above for details about the MGD77T format and citation information.)
    SURVEY_ID
    Survey identifier supplied by the contributing organization (Source: NGDC) This identifier varies in format and is supplied by the contributing organization
    TIMEZONE
    Time-zone correction (Source: NGDC) In our datasets, no correction was applied. All values equal 0.
    DATE
    YYYYMMDD (Source: NGDC)
    Range of values
    Minimum:19820922
    Maximum:19821005
    Units:Year, month, day
    TIME
    Time (Source: NGDC)
    Range of values
    Minimum:0
    Maximum:2359.783
    Units:hours and decimal minutes
    LAT
    Latitude (Source: World Geodetic System 1984 Geographic Coordinate System)
    Range of values
    Minimum:52.53880
    Maximum:55.33219
    Units:decimal degrees
    LON
    Longitude (Source: World Geodetic System 1984 Geographic Coordinate System)
    Range of values
    Minimum:-166.52713
    Maximum:-158.30485
    Units:decimal degrees
    POS_TYPE
    Indicates how lat/lon was obtained (Source: NGDC)
    Range of values
    Minimum:1
    Maximum:3
    Units:1 = observed fix, 3 = interpolated fix, nil = unspecified
    BAT_TTIME
    Bathymetry, 2-way travel time (Source: U.S. Geological Survey)
    Range of values
    Minimum:0.027
    Maximum:9.264
    Units:seconds
    CORR_DEPTH
    Bathymetry, corrected depth (Source: U.S. Geological Survey)
    Range of values
    Minimum:19.4
    Maximum:6777.3
    Units:decimal meters
    BAT_CPCO
    Bathymetric Correction code - details the procedure used for determining the sound velocity correction to depth (Source: NGDC)
    Range of values
    Minimum:59
    Maximum:59
    Units:01-55 Matthews' Zones with zone , 59 Matthews' Zones, no zone specified, 60 S. Kuwahara Formula, 61 Wilson Formula, 62 Del Grosso Formula, 63 Carter's Tables, 88 Other (see Add. Doc.), 97 Computed using 1500 meters/sec, 98 Unknown if Corrected, 99 Unspecified
    BAT_TYPCO
    Bathymetry type code - indicates how the bathymetric value was obtained (Source: NGDC)
    Range of values
    Minimum:1
    Maximum:3
    Units:1 - Observed, 3 - Interpolated (Header Seq. 12), 9 - Unspecified
    MAG_TOT
    Magnetics total field - 1st sensor (Source: NGDC)
    Range of values
    Minimum:49780
    Maximum:52163.5
    Units:gammas
    MAG_RES
    Magnetics residual field field (Source: NGDC)
    Range of values
    Minimum:-383.7
    Maximum:1291.8
    Units:gammas
    GRA_OBS
    Observed gravity (Source: NGDC)
    Range of values
    Minimum:981163.2
    Maximum:981689.6
    Units:milligals
    EOTVOS
    EOTVOS correction - E = 7.5 V cos(phi) * sin(alpha) + 0.0042 V*V (Source: NGDC)
    Range of values
    Minimum:-24.6
    Maximum:26.9
    Units:milligals
    FREEAIR
    Free-air Anomaly = G(observed) minus G(theoretical) (Source: NGDC)
    Range of values
    Minimum:-148.7
    Maximum:226.3
    Units:milligals
    LINEID
    LINE/TRACK/SEGMENT ID (Source: NGDC)
    Range of values
    Minimum:201
    Maximum:217
    Units:Used, for example, to cross reference with seismic data.
    POINTID
    SEISMIC SHOT-POINT NUMBER/POINT ID (Source: NGDC)
    Range of values
    Minimum:2704
    Maximum:2984
    Units:Used, for example, to cross reference with seismic data.
    Entity_and_Attribute_Overview:
    Bathymetry, gravity, magnetic, and navigation data for U.S. Geological Survey bathymetry survey L1282WG in MGD77T format.
    Entity_and_Attribute_Detail_Citation:
    Attributes are obtained from MGD77T data files created from the navigation gravity, magnetic, and bathymetry best files. MGD77T is the standard, defined data format used for geophysical data in the National Geophysical Data Center. See Cross_Reference section above for citation details.

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • U.S. Geological Survey
    • Coastal and Marine Geology Program
  2. Who also contributed to the data set?
    Steve Lewis (Chief Scientist, Lamont-Doherty); Terry Bruns (Chief Scientist)
  3. To whom should users address questions about the data?
    Gregory K. Miller
    U.S. Geological Survey
    Physical Scientist
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 803-8747, ext. 3020 (voice)
    gmiller@usgs.gov

Why was the data set created?

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/ ).

How was the data set created?

  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
    Date: 19-Jan-1996 (process 1 of 6)
    Navigation Data >Converted to time format with year at start. > >07/02/85 KAYE DRS$DATA:[L1282WG.N]LC82WG.052; >DRB0:[DRS.REFMT]REFORMAT.EXE;4 >Original file name is l1282wg.sinsc1._. > Person who carried out this activity:
    U.S. Geological Survey (USGS) , Coastal and Marine Geology (CMG)
    Attn: Carolyn H. Degnan
    Geophysicist
    USGS Pacific Coastal & Marine Science Center, 400 Natural Bridges Drive
    Santa Cruz, CA
    USA

    (831) 460-7452 (voice)
    (831) 427-4748 (FAX)
    infobank@octopus.wr.usgs.gov
    Date: 31-Oct-1998 (process 2 of 6)
    Gravity Data >10/31/1998 /tiger/l/l1282wg/grav/l-12-82-wg.151_052 >/bear/programs/edit/automerge/automerge > >Input was... >Converted to time format with year at start. > >10/10/85 BARB DRS$DATA:[LC82WG.G]LC82WG.151; >DRB0:[DRS.REFMT]REFORMAT.EXE;4 > >Input was... >Converted to time format with year at start. > >07/02/85 KAYE DRS$DATA:[L1282WG.N]LC82WG.052; >DRB0:[DRS.REFMT]REFORMAT.EXE;4 >Original file name is l1282wg.sinsc1._. > >time, lat, long, time(sec) to nearest nav fix, data values Person who carried out this activity:
    U.S. Geological Survey (USGS) , Coastal and Marine Geology (CMG)
    Attn: Carolyn H. Degnan
    Geophysicist
    USGS Pacific Coastal & Marine Science Center, 400 Natural Bridges Drive
    Santa Cruz, CA
    USA

    (831) 460-7452 (voice)
    (831) 427-4748 (FAX)
    infobank@octopus.wr.usgs.gov
    Date: 20-Jun-2012 (process 3 of 6)
    Magnetics Data >06/20/2012 carolyn l-12-82-wg.220_052 > >Reprocessed using subroutines from Susan Macmillan's >IGRF SYNTHESIS PROGRAM http://www.ngdc.noaa.gov/IAGA/vmod/igrf11.f >with IGRF-11 coeffiecients integrated into the source code. >/infobank/programs/mag/magred11/magred11.for >Using geodetic coordinate system (Earth shape approximated by spheriod) >with altitude 0.0 km (for sea level). > >Input was... >10/31/1998 /tiger/l/l1282wg/mag/l-12-82-wg.200_052 >/bear/programs/edit/automerge/automerge > >Converted to time format with year at start. > >10/03/85 CAROLYN DRS$DATA:[L1282BS.M]LC82WG.200; >DRB0:[DRS.REFMT]REFORMAT.EXE;4 >was L1282WG._.MAGSB1 on TAM415 >was LB82WG240.DAT on VAM415 > >Converted to time format with year at start. > >07/02/85 KAYE DRS$DATA:[L1282WG.N]LC82WG.052; >DRB0:[DRS.REFMT]REFORMAT.EXE;4 >Original file name is l1282wg.sinsc1._. > >time, lat, long, time(sec) to nearest nav fix, data values Person who carried out this activity:
    U.S. Geological Survey (USGS) , Coastal and Marine Geology (CMG)
    Attn: Carolyn H. Degnan
    Geophysicist
    USGS Pacific Coastal & Marine Science Center, 400 Natural Bridges Drive
    Santa Cruz, CA
    USA

    (831) 460-7452 (voice)
    (831) 427-4748 (FAX)
    infobank@octopus.wr.usgs.gov
    Date: 31-Oct-1998 (process 4 of 6)
    Bathymetry Data >10/31/1998 /tiger/l/l1282wg/bath/l-12-82-wg.320_052 >/bear/programs/edit/automerge/automerge > >Input was... >Converted to time format with year at start. > >07/16/85 BECKIE DUA0:[DATA.L1282WG.B]LC82WG.320; >DRB0:[DRS.REFMT]REFORMAT.EXE;4 >I BELIEVE THIS FILE TO BE HAND-DIGETIZED BATHY IN 2-WAY >TRAVEL-TIME. I DO NOT KNOW WHAT MATHEWS AREA WAS USED >TO CALCULATE THE CORRECTED DEPTHS. R.LARSEN > >Input was... >Converted to time format with year at start. > >07/02/85 KAYE DRS$DATA:[L1282WG.N]LC82WG.052; >DRB0:[DRS.REFMT]REFORMAT.EXE;4 >Original file name is l1282wg.sinsc1._. > >time, lat, long, time(sec) to nearest nav fix, data values Person who carried out this activity:
    U.S. Geological Survey (USGS) , Coastal and Marine Geology (CMG)
    Attn: Carolyn H. Degnan
    Geophysicist
    USGS Pacific Coastal & Marine Science Center, 400 Natural Bridges Drive
    Santa Cruz, CA
    USA

    (831) 460-7452 (voice)
    (831) 427-4748 (FAX)
    infobank@octopus.wr.usgs.gov
    Date: 20-Jun-2012 (process 5 of 6)
    MGD77 file creation - 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 interpolated. 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. Person who carried out this activity:
    U.S. Geological Survey (USGS), Coastal and Marine Geology (CMG)
    Attn: Carolyn H. Degnan
    Geophysicist
    USGS Pacific Coastal & Marine Science Center, 400 Natural Bridges Drive
    Santa Cruz, CA
    USA

    (831) 460-7452 (voice)
    (831) 427-4748 (FAX)
    infobank@octopus.wr.usgs.gov
    Date: 01-Feb-2017 (process 6 of 6)
    Keywords section of metadata optimized for discovery in USGS Coastal and Marine Geology Data Catalog. Person who carried out this activity:
    U.S. Geological Survey
    Attn: Alan O. Allwardt
    Contractor -- Information Specialist
    2885 Mission Street
    Santa Cruz, CA

    831-460-7551 (voice)
    831-427-4748 (FAX)
    aallwardt@usgs.gov
  3. What similar or related data should the user be aware of?
    Hittelman, Allen M., Groman, Robert C., Haworth, Richard T., Holcombe, Troy L., McHendrie, Graig, Smith, Stuart M., and Metzger, Dan R., 2010, The marine geophysical data exchange format - MGD77 / MGD77T: National Geophysical Data Center, National Oceanic and Atmospheric Administration, Boulder, CO.

    Online Links:

    Other_Citation_Details: 25 p.

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?
    The validity or accuracy of bathymetry and navigation data is highly qualitative and depends on equipment and operating condition variables. Data quality is unknown, MGD77T files were formatted from InfoBank files identified as best available version.
  2. How accurate are the geographic locations?
    Unspecified
  3. How accurate are the heights or depths?
    Unspecified
  4. Where are the gaps in the data? What is missing?
    Start and end date/times of data >Navigation Data (l-12-82-wg.052 [SINS]) >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >198209222208000 198209251241200 >198209251250390 198209280116290 >198209280148000 198210052144000 >198210052247000 198210052247000 >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >Gravity Data (l-12-82-wg.151_052) >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >198209230336000 198209240016480 >198209240026000 198209240047000 >198209240058000 198209240142000 >198209250000120 198209250000120 >198209260000000 198209260549480 >198209260839000 198209261517000 >198209261538000 198209261653000 >198209261737240 198209261915240 >198209261936240 198209262016240 >198209262031240 198209262123240 >198209262223240 198209262324240 >198209262351240 198209270236240 >198209270253240 198209271115000 >198209271142000 198209271951000 >198209272023480 198209272138000 >198209272253540 198209272253540 >198209281312180 198209281312180 >198209282040180 198209282040180 >198209282227240 198209282351240 >198209290009240 198209290840000 >198209291108000 198209292105120 >198209292134120 198209292325120 >198209292330540 198209300109540 >198209300208540 198209300732540 >198209300819480 198209301600000 >198209301611480 198209301752480 >198209301804480 198209302136480 >198209302152480 198210010222000 >198210010258240 198210011655000 >198210011703120 198210012018420 >198210012037420 198210020157420 >198210020251420 198210020929120 >198210020950120 198210021119120 >198210021151120 198210022046540 >198210022144000 198210030648480 >198210030741480 198210031942480 >198210032040480 198210040024480 >198210040051480 198210040310420 >198210040325360 198210042202240 >198210042213240 198210050134360 >198210050155360 198210050433000 >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >Magnetics Data (l-12-82-wg.220_052) >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >198209230916570 198209240022210 >198209240030570 198209240915250 >198209240921490 198209241808050 >198209241818130 198209251154100 >198209251159260 198209260554580 >198209260844020 198209261658220 >198209261742260 198209271956140 >198209272028460 198209280131300 >198209282100190 198209300738170 >198209300824450 198210022051530 >198210022149010 198210040030450 >198210040056490 198210050331290 >198210050631300 198210052030500 >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >Bathymetry Data (l-12-82-wg.320_052) >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >Seismic Shots Data (l-12-82-wg.422_052) >YYYYMMDDHHMMSST YYYYMMDDHHMMSST >198209230950150 198209231801360 >198209231811240 198209231817090 >198209231833290 198209231910080 >198209231944280 198209232022110 >198209232059590 198209232136270 >198209232214290 198209232253390 >198209232334500 198209240013140 >198209240056480 198209240142090 >198209240230370 198209240546310 >198209240645060 198209241433310 >198209241525280 198209242059370 >198209242110000 198209242153490 >198209242218500 198209251237530 >198209251330450 198209251648000 >198209251715510 198209251755190 >198209251823490 198209251838230 >198209251904470 198209260937180 >198209261003080 198209261048030 >198209261120070 198209261207290 >198209261255430 198209261348500 >198209261440060 198209261520060 >198209261654300 198209261741250 >198209261824540 198209262115170 >198209262220110 198209271118080 >198209271205160 198209280054120 >198209282027120 198209290134460 >198209290225140 198209290733510 >198209290757190 198209292100030 >198209292140240 198209300114470 >198209300220180 198209301059540 >198209301200290 198209301345470 >198209301420120 198209302241590 >198209302320070 198210010154590 >198210010255090 198210012019330 >198210012105350 198210020200050 >198210020300430 198210020935590 >198210021003170 198210021119540 >198210021215190 198210030644410 >198210030745240 198210031950200 >198210032039570 198210040307030 >198210040337240 198210041915190 >198210041940000 198210050110030 >198210050205200 198210050329540 >YYYYMMDDHHMMSST YYYYMMDDHHMMSST
  5. How consistent are the relationships among the observations, including topology?
    This data set is from one field activity with unknown instrument calibrations. Processed bathymetric depths were spot checked based on latitude and longitude against the Global Multi-Resolution Topography (GMRT) grid within GeoMapApp to ensure reasonable values.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
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 these data should not violate the spatial resolution of the data. Where these data are used in combination with other data of different resolution, the resolution of the combined output will be limited by the lowest resolution 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. Geological Survey.This database has been approved for release and publication by the Director of the USGS. Although this database has been subjected to rigorous review and is substantially complete, the USGS reserves the right to revise the data pursuant to further analysis and review. Furthermore, it is released on condition that neither the USGS nor the United States Government may be held liable for any damages resulting from its authorized or unauthorized use.Although this Federal Geographic Data Committee-compliant metadata file is intended to document these data in nonproprietary form, as well as in ArcInfo format, this metadata file may include some ArcInfo-specific terminology.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey
    345 Middlefield Road MS 999
    Menlo Park, CA
    USA

    (650) 329-5078 (voice)
    (650) 329-5190 (FAX)
  2. What's the catalog number I need to order this data set? Downloadable Data
  3. What legal disclaimers am I supposed to read?
    Neither the U.S. Government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. 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.
  4. How can I download or order the data?

Who wrote the metadata?

Dates:
Last modified: 01-Feb-2017
Metadata author:
Gregory K. Miller
U.S. Geological Survey
Physical Scientist
U.S. Geological Survey, 600 Fourth Street South
St. Petersburg, FL
USA

(727) 803-8747, ext. 3020 (voice)
gmiller@usgs.gov
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)

This page is <https://cmgds.marine.usgs.gov/catalog/pcmsc/830.faq.html>
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