U.S. Geological Survey
Coastal and Marine Geology Program
2013
g295sf.m77t and g295sf.h77t: MGD77T data and header files for single-beam bathymetry data for field activity G-2-95-SF in San Francisco Bay, Golden Gate from 05/30/1995 to 06/10/1995
tab-delimited ASCII text files
St. Petersburg, FL
U.S. Geological Survey
http://pubs.usgs.gov/ds/757/data/m77t/g295sf.m77t
Heather A. Schreppel
Carolyn H. Degnan
Dan R. Metzger
Shawn V. Dadisman
2013
Archive of U.S. Geological Survey selected single-beam bathymetry datasets, 1969-2000
1.0
Digital Document
U.S. Geological Survey Data Series
757
St. Petersburg, FL
U.S. Geological Survey
http://pubs.usgs.gov/ds/757
Single-beam bathymetry data along with GPS navigation data was collected as part of the U.S. Geological Survey cruise G-2-95-SF. The cruise was conducted in San Francisco Bay, Golden Gate area from May 30 to June 10, 1995. The chief scientists were Terry Bruns, Paul Carlson, and Dennis Mann all from the USGS Coastal and Marine Geology office in Menlo Park, CA.
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/g/g295sf/html/g-2-95-sf.meta.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 Global Positioning System (GPS). The GPS is a space-based satellite navigation system maintained by the United States government and is accessible using a GPS receiver. Data accuracy is based on individual receiver models, and most GPS data are collected in the WGS84 horizontal datum.
The Data Acquisition, 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 (.0xx, .6xx) space-delimited ASCII data file. The header information rows are indicated by lines beginning with the character "!". The single-beam bathymetry data are collected both digitally and as analog records, the system used is unknown. The bathymetry datasets were commonly processed using three programs: (A) Batred, which calculates depth from travel times; (B) nosamebathy, which eliminates identical adjacent bathymetry values; and (C) nozerobathy, which removes records with a depth value of "0.0". However, not all of the datasets included in this report were processed with one or more of these programs. If the data was not run through these programs it was reformatted using the most recent "best file" on InfoBank, often these were categorized by InfoBank as raw bathymetry files. Details about which processing steps were taken by the DAPS group can be found in the header information of the bathymetry and navigation ASCII files downloaded from InfoBank.
Prior to reformatting the data into MGD77T format the "best" bathymetry and navigation files from InfoBank were edited to remove the header information and reformatted using Excel 2010 to separate the data into columns based on tabs. Next the bathymetry and navigation files were merged based on time and latitude and longitude. The combined navigation and bathymetry was saved as a .txt file. This combined bathymetry and navigation file was used as an input file into the GEODAS ReFormat to MDG77T program developed by NOAA's NGDC. The program outputs the reformatted data as a tab-delimited .m77t file. The program is available for use at: http://www.ngdc.noaa.gov/mgg/gdas/gx_announce.Html. For information regarding fields found within the MGD77T files, please refer to the publication, Hittelman and others (2010), found within the Cross-reference section of this metadata file.
Each MGD77T data file also has an accompanying header file (.h77t). The fields within these header files are also defined in the aforementioned publication. Fields are populated based on InfoBank metadata records, digital data file headers, and accompanying publications (often cruise reports) for the survey. If a field is unknown or did not apply to the dataset it is intentionally left blank.
19950530
19950610
ground condition
None planned
-122.76216
-121.68708
38.15448
37.49707
USGS Metadata Identifier
USGS:da4a3bc9-f206-4599-bfa0-2fd3669c6898
ISO 19115 Topic Category
geoscientificinformation
oceans
None
Marine Geology
Marine Geophysics
Single-beam Bathymetry
Water Depth
Seafloor Topography
Data Categories for Marine Planning
distributions
bathymetry and elevation
Marine Realms Information Bank (MRIB) Keywords
single-beam echo sounder
marine geophysics
USGS Thesaurus
single-beam echo sounder
bathymetry measurement
bathymetry
marine geophysics
Geographic Names Information System (GNIS)
State of California
San Francisco Bay
Northern California
City of San Francisco
None. These data are held in the public domain.
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.
Heather A. Schreppel
Cherokee Nation Technology Solutions, contracted to U.S. Geological Survey
IT Management Specialist/Database Support Assistant
mailing and physical
600 4th Street South
St. Petersburg
FL
33701
USA
(727) 803-8747, ext. 3013
hschreppel@usgs.gov
Terry Bruns (Chief Scientist, USGS Western Region);
Paul Carlson (Chief Scientist, USGS Western Region);
Dennis Mann (Chief Scientist, USGS Western Region);
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
Boulder, CO
National Geophysical Data Center, National Oceanic and Atmospheric Administration
25 p.
http://www.ngdc.noaa.gov/mgg/dat/geodas/docs/mgd77.pdf
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.
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.
Start and end date/times of data according to DAPS group. Reasons for gaps in data varies by cruise, see InfoBank for more details.
>Navigation Data (g-2-95-sf.062 [GPS])
>YYYYMMDDHHMMSST YYYYMMDDHHMMSST
>199505310323080 199506011851332
>199506011905572 199506012021080
>199506012356530 199506022019392
>199506022034599 199506032012580
>199506032239470 199506040011160
>199506040018450 199506040244240
>199506040255270 199506041023286
>199506041032370 199506041112300
>199506041121230 199506041141130
>199506041150240 199506051226494
>199506052101230 199506052228470
>199506052248500 199506052258440
>199506052308230 199506060402390
>199506060418160 199506060438060
>199506060448130 199506060458040
>199506060503280 199506061114290
>199506061122190 199506061132090
>199506061141090 199506061808070
>199506061818470 199506061851460
>199506061859120 199506061910500
>199506062152590 199506062212590
>199506062220530 199506062232500
>199506062351160 199506070057504
>199506070108010 199506072039120
>199506072107580 199506091004006
>YYYYMMDDHHMMSST YYYYMMDDHHMMSST
>Bathymetry Data (g-2-95-sf.300_062)
>YYYYMMDDHHMMSST YYYYMMDDHHMMSST
>199505310323080 199505310540120
>199505310545200 199505311431173
>199505311515288 199506010559275
>199506011424010 199506011851332
>199506020809222 199506022019392
>199506022035110 199506032014320
>199506032249510 199506032259010
>199506032331350 199506040011160
>199506040224340 199506040244240
>199506040315280 199506041023286
>199506041032370 199506041112300
>199506041121230 199506041141130
>199506041150240 199506051226494
>199506052108560 199506052228470
>199506052248500 199506052258440
>199506052319060 199506052353035
>199506060418160 199506060438060
>199506060448130 199506060458040
>199506060503280 199506061114290
>199506061122190 199506061132090
>199506061141090 199506061808370
>199506070032510 199506070057504
>199506070120474 199506070153114
>YYYYMMDDHHMMSST YYYYMMDDHHMMSST
Unspecified
Unspecified
Below are the details about which processing steps were taken by the DAPS group that can be found in the header information of the ASCII files downloaded from InfoBank.
Navigation Data
>Converted to time format with year at start.
>
19960221
U.S. Geological Survey (USGS), Coastal and Marine Geology (CMG)
Carolyn H. Degnan
Geophysicist
mailing and physical address
USGS Pacific Coastal & Marine Science Center, 400 Natural Bridges Drive
Santa Cruz
CA
95060-5792
USA
(831) 460-7452
(831) 427-4748
infobank@octopus.wr.usgs.gov
Below are the details about which processing steps were taken by the DAPS group that can be found in the header information of the ASCII files downloaded from InfoBank.
Bathymetry Data
>10/31/1998 /tiger/g/g295sf/bath/g-2-95-sf.300_062
>/bear/programs/edit/automerge/automerge
>
>Input was...
>Converted to time format with year at start.
>
>Input was...
>Converted to time format with year at start.
>
>time, lat, long, time(sec) to nearest nav fix, data values
19981031
U.S. Geological Survey (USGS), Coastal and Marine Geology (CMG)
Carolyn H. Degnan
Geophysicist
mailing and physical address
USGS Pacific Coastal & Marine Science Center, 400 Natural Bridges Drive
Santa Cruz
CA
95060-5792
USA
(831) 460-7452
(831) 427-4748
infobank@octopus.wr.usgs.gov
A navigation file identified as the best available version in InfoBank for this cruise was copied and saved as an ASCII text file to be combined with the best available bathymetry file for processing to MGD77T format. For details regarding processing steps performed on these best available files from InfoBank, please see the header information within the original files at http://walrus.wr.usgs.gov/infobank/ and previous processing steps.
g-2-95-sf.062.txt
2012
g295sfnav.txt
Cherokee Nation Technology Solutions, contracted to the U.S. Geological Survey
Heather A. Schreppel
IT Management Specialist/Database Support Assistant
mailing and physical address
600 4th Street South
St. Petersburg
FL
33701
USA
727-803-8747 ext. 3013
hschreppel@usgs.gov
A bathymetry file identified as the best available version in InfoBank for this cruise was copied and saved as an ASCII text file to be combined with the best available navigation file for processing to MGD77T format. For details regarding processing steps performed on these best available files from InfoBank, please see the header information within the original files at http://walrus.wr.usgs.gov/infobank/.
g-2-95-sf.300_062.txt
2012
g295sfbathy.txt
Cherokee Nation Technology Solutions, contracted to the U.S. Geological Survey
Heather A. Schreppel
IT Management Specialist/Database Support Assistant
mailing and physical address
600 4th Street South
St. Petersburg
FL
33701
USA
727-803-8747 ext. 3013
hschreppel@usgs.gov
The best available bathymetry and navigation text files were concatenated into one tab-delimited file using Excel 2010 and several Visual Basic Applications (VBA) macros. InfoBank header information is removed and text is broken into columns and the rows are combined based on the presence of the same values in the time and latitude and longitude columns.
g295sfbathy.txt, g295sfnav.txt
2012
g295sfall.txt
Cherokee Nation Technology Solutions, contracted to the U.S. Geological Survey
Heather A. Schreppel
IT Management Specialist/Database Support Assistant
mailing and physical address
600 4th Street South
St. Petersburg
FL
33701
USA
727-803-8747 ext. 3013
hschreppel@usgs.gov
The combined bathymetry and navigation file was used as an input file into the GEODAS ReFormat to MDG77T program developed by NOAA's NGDC. The program outputs the reformatted data as a tab-delimited .m77t file. The program is available for use at: http://www.ngdc.noaa.gov/mgg/gdas/gx_announce.Html
g295sfall.txt
2012
g295sf.m77t
Cherokee Nation Technology Solutions, contracted to the U.S. Geological Survey
Heather A. Schreppel
IT Management Specialist/Database Support Assistant
mailing and physical address
600 4th Street South
St. Petersburg
FL
33701
USA
727-803-8747 ext. 3013
hschreppel@usgs.gov
To create the accompanying header files (.h77t), an excel spreadsheet was supplied from NGDC with already populated required field names. For information for header field requirements and definitions see: http://www.ngdc.noaa.gov/mgg/dat/geodas/docs/mgd77.pdf. When creating a header file for each cruise, fields were populated in the header spreadsheet based on InfoBank metadata records, digital data file headers, and accompanying publications (often cruise reports) for the survey. If a field was unknown or did not apply to the dataset it was intentionally left blank.
http://walrus.wr.usgs.gov/infobank/g/g295sf/html/g-2-95-sf.meta.html
2012
g295sf.h77t
Cherokee Nation Technology Solutions, contracted to the U.S. Geological Survey
Heather A. Schreppel
IT Management Specialist/Database Support Assistant
mailing and physical address
600 4th Street South
St. Petersburg
FL
33701
USA
727-803-8747 ext. 3013
hschreppel@usgs.gov
Keywords section of metadata optimized for discovery in USGS Coastal and Marine Geology Data Catalog.
20161229
U.S. Geological Survey
Alan O. Allwardt
Contractor -- Information Specialist
mailing and physical address
2885 Mission Street
Santa Cruz
CA
95060
831-460-7551
831-427-4748
aallwardt@usgs.gov
Added keywords section with USGS persistent identifier as theme keyword.
20201013
U.S. Geological Survey
VeeAnn A. Cross
Marine Geologist
Mailing and Physical
384 Woods Hole Road
Woods Hole
MA
02543-1598
508-548-8700 x2251
508-457-2310
vatnipp@usgs.gov
San Francisco Bay, Golden Gate from 05/30/1995 to 06/10/1995
Point
Point
0.000001
0.000001
Decimal degrees
D_WGS_1984
WGS_1984
6378137.000000
298.25722210100002
g295sf.m77t
MGD77T single-beam bathymetry data file for G295SF
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
NGDC
This identifier varies in format and is supplied by the contributing organization
TIMEZONE
Time-zone correction
NGDC
In our datasets, no correction was applied. All values equal 0.
DATE
Survey Date
NGDC
19950531
19950609
YYYYMMDD, (four digit year, two digit month, two digit day)
TIME
Time
NGDC
0
2359.995
hours and decimal minutes
LAT
Latitude
World Geodetic System 1984 Geographic Coordinate System
37.49707
38.15448
decimal degrees
LON
Longitude
World Geodetic System 1984 Geographic Coordinate System
-122.76216
-121.68708
decimal degrees
POS_TYPE
Indicates how lat/lon was obtained
NGDC
1
Observed fix
NGDC
3
Interpolated fix
NGDC
nil
unspecified
NGDC
BAT_TTIME
Bathymetry, 2-way travel time
U.S. Geological Survey
0.00267
0.15067
seconds
g-2-95-sf.h77t
MGD77T single-beam bathymetry header file for G-2-95-SF
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
NGDC
This identifier varies in format and is supplied by the contributing organization
FORMAT_77
Format Acronym
NGDC
Text string description
PARAMS_CO
Parameters surveyed codes.
NGDC
Status of geophysical parameters for this survey. See Hittelman and others (2010) from the Cross_Reference section above for details.
INST_SRC
Source Institution
NGDC
Text string description
COUNTRY
Country
NGDC
Text string description
PLATFORM
Platform name
NGDC
Text string description
PLAT_TYPCO
Platform type code
NGDC
nil
Unspecified
NGDC
1
Surface Ship
NGDC
2
Submersible Ship
NGDC
3
Aircraft
NGDC
4
Buoy
NGDC
5
Mobile land
NGDC
6
Fixed land
NGDC
7
Deep tow
NGDC
PLAT_TYP
Platform type
NGDC
Text string description
CHIEF
Chief Scientist(s)
NGDC
Text string description
PROJECT
Project, cruise, leg
NGDC
Text string description
FUNDING
funding
NGDC
Text string description
DATE_DEP
survey departure date
NGDC
19770427
20000629
YYYYMMDD (four digit year, two digit month, two digit day)
PORT_DEP
port of departure
NGDC
Text string description
DATE_ARR
survey arrival date
NGDC
19770427
20000629
YYYYMMDD (four digit year, two digit month, two digit day)
PORT_ARR
port of arrival
NGDC
Text string description
NAV_INSTR
navigation instrumentation
NGDC
Text string description
POS_INFO
position determination method/ geodetic datum
NGDC
Text string description
BATH_INSTR
bathymetry instrumentation
NGDC
Text string description
BATH_ADD
additional forms of bathymetry
NGDC
Text string description
LAT_TOP
Latitude
World Geodetic System 1984 Geographic Coordinate System
16.38240
89.98766
decimal degrees
LAT_BOTTOM
Latitude
World Geodetic System 1984 Geographic Coordinate System
16.38240
89.98766
decimal degrees
LON_LEFT
Longitude
World Geodetic System 1984 Geographic Coordinate System
10.30551
-117.13802
decimal degrees
LON_RIGHT
Longitude
World Geodetic System 1984 Geographic Coordinate System
10.30551
-117.13802
decimal degrees
BATH_DRATE
general digitizing rate of bathymetry
NGDC
Text string description
SOUND_VEL
assumed sound velocity
NGDC
Text string description
VDATUM_CO
bathymetric vertical datum
NGDC
In our datasets, no correction was applied. All values equal 0.
Bathymetry and navigation data for U.S. Geological Survey bathymetry survey G-2-95-SF in MGD77T format.
Attributes are obtained from MGD77T data files created from the navigation and bathymetry best files. MGD77T is the standard, defined data format used for geophysical data in the National Geophysical Data Center. The MGD77T format contains more attributes than defined here. Attributes that were null for this data were not included. Details about other attributes can be found in Hittelman and others (2010), see Cross_Reference section above for citation details.
20201013
Heather A. Schreppel
Cherokee Nation Technology Solutions, contracted to the U.S. Geological Survey
IT Management Specialist/Database Support Assistant
mailing and physical address
U.S. Geological Survey, 600 Fourth Street South
St. Petersburg
FL
33701
USA
(727) 803-8747, ext. 3013
hschreppel@usgs.gov
FGDC Content Standards for Digital Geospatial Metadata
FGDC-STD-001-1998