MGD77INFO

mgd77info − Get information about MGD77[+] files

mgd77info NGDC-ids [ −C[m|e] ] [ −E[m|e] ] [ −Iignore ] [ −Mf[item]|r ] [ −L[v] [ −V ]

mgd77info reads <legid>.[mgd77|nc] files and produces a single record of information about each cruise specified. The information includes beginning and end times, total track distances in km, longitude and latitude range, and the total number of geophysical observations. Optionally, choose instead to see the original MGD77 header meta-data section or its individual members.
If you need to know which tracks are crossing through a given region and what kinds of geophysical observations are available, consider using the x2sys tools to set up a tracks index data base (see x2sys_init for more information).

NGDC-ids

Can be one or more of five kinds of specifiers:
1) 8-character NGDC IDs, e.g., 01010083, JA010010etc., etc.
2) 2-character <agency> codes which will return all cruises from each agency.
3) 4-character <agency><vessel> codes, which will return all cruises from those vessels.
4) =<list>, where <list> is a table with NGDC IDs, one per line.
5) If nothing is specified we return all cruises in the data base.
(See mgd77info −F for agency and vessel codes). The ".mgd77" or ".nc" extensions will automatically be appended, if needed (use −I to ignore certain file types). Cruise files will be looked for first in the current directory and second in all directories listed in $MGD77_HOME/mgd77_paths.txt [If $MGD77_HOME is not set it will default to $GMTHOME/share/mgd77].
NOTE: Under Windows, only (1) and (4) are currently supported.

No space between the option flag and the associated arguments.

−C

List abbreviations for all columns present in the MGD77[+] files. Append m or e to limit the display to the MGD77 standard or MGD77+ extended set only.

−E

Give a one-line summary for each cruise listed.

−M

List the meta-data (header) and (if present) the MGD77+ history for each cruise. Append f for a formatted display. This will list individual parameters and their values, one entry per output line, in a format that can be searched using standard UNIX text tools. Alternatively, append the name of a particular parameter (you only need to give enough characters - starting at the beginning - to uniquely identify the item). Give - to display the list of all parameter names. You may also specify the number of a parameter. For the raw, punchcard-formatted MGD77 original header block, append r instead.

−I

Ignore certain data file formats from consideration. Append a|c|t to ignore MGD77 ASCII, MGD77+ netCDF, or plain tab-separated ASCII table files, respectively. The option may be repreated to ignore more than one format. [Default ignores none].

−L

No cruise information is listed. Instead, we just display a list of the GEODAS institution 2-character codes and their names. Optionally, append v to also display the vessels and their 4-character codes for each institution. The following is the list of institutions:

(01) LAMONT (LDEO), (02) WOODS HOLE O.I., (03) NOAA, (04) US ARMY, (05) NEW ZEALAND, (06) US GEOL. SURVEY, (07) OREGON ST. UNIV, (08) U.HAWAII SOEST, (09) US NAVY, (10) UNIV OF TEXAS, (11) RICE UNIV., (12) CANADA, (13) UNIV OF CONN., (14) U.MIAMI (RSMAS), (15) SCRIPPS INST.OC, (16) CHINA, (17) U RHODE ISLAND, (18) DUKE UNIVERSITY, (19) UNITED KINGDOM, (20) U.WASHINGTON, (22) WESTERN GEOPHY., (23) TEXAS A&M UNIV., (24) AUSTRALIA, (25) MONACO, (29) RUSSIA, (30) SPAIN, (35) NIMA, (58) NETHERLANDS, (60) MIN MGMT SVC, (63) ISRAEL, (67) FRANCE, (71) SOUTH AFRICA, (75) US COAST GUARD, (76) BRAZIL, (77) INT. GRAV. BUR, (83) GERMANY, (84) ORSTOM NEW CAL, (86) CUBA, (87) ARGENTINA, (88) US NSF, (89) INDIA, (90) PORTUGAL, (92) FINLAND, (93) CHILE, (J1) HYDR DEPT JAPAN, (J2) GEOL SRVY JAPAN, (J4) UNIV TOKYO, (J5) KOBE UNIV, (J7) UNIV OF RYUKYUS, (J8) J.O.D.C. JAPAN, (J9) CHIBA UNIV, (JA) INST.POLAR RES., (ZZ) INST NOT CODED.

−V

Selects verbose mode, which will send progress reports to stderr [Default runs "silently"].

To get one-line summary information about the cruises 01010047.mgd77 and 01010008.mgd77, try

mgd77info 01010047 01010008 −E > listing.lis

To see the original raw MGD77 header meta-data for cruise 01010047.mgd77, run

mgd77info 01010047 −Mr

To determine all the parameters related to Gravity during cruise 01010047.mgd77, run

mgd77info 01010047 −Mf | grep Gravity

To determine the Magnetic sampling rate used during cruise 01010047.mgd77, run

mgd77info 01010047 −MfMagnetics_Sampling_Rate

To see all the columns that the MGD77+ cruise 01010047.nc contains, run

mgd77info 01010047.nc −C

mgd77list(l), mgd77manage(l), mgd77path(l), mgd77track(l) x2sys_init(l)

Wessel, P., and W. H. F. Smith, 2005, The Generic Mapping Tools (GMT) version 4.1 Technical Reference & Cookbook, SOEST/NOAA.
Wessel, P., and W. H. F. Smith, 1998, New, Improved Version of Generic Mapping Tools Released, EOS Trans., AGU, 79 (47), p. 579.
Wessel, P., and W. H. F. Smith, 1995, New Version of the Generic Mapping Tools Released, EOS Trans., AGU, 76 (33), p. 329.
Wessel, P., and W. H. F. Smith, 1995, New Version of the Generic Mapping Tools Released, http://www.agu.org/eos_elec/95154e.html, Copyright 1995 by the American Geophysical Union.
Wessel, P., and W. H. F. Smith, 1991, Free Software Helps Map and Display Data, EOS Trans., AGU, 72 (41), p. 441.
The Marine Geophysical Data Exchange Format - "MGD77", see http://www.ngdc.noaa.gov/mgg/dat/geodas/docs/mgd77.txt