mgd77header¶
mgd77header - Generate MGD77 header from data records
Synopsis¶
mgd77header NGDC-id.a77 [ -Hheadervalues.txt ] [ -Mf[item]|r|t ] [ -V[level] ]
Note: No space is allowed between the option flag and the associated arguments.
Description¶
mgd77header generates an MGD77 header by reading A77 data (i.e., the data record portion of MGD77 files), determines temporal and spatial extents, ten degree boxes crossed, and data columns present. Optionally, it can also read an input file consisting of header field values (-H) to be included in program output. Header field values determined from data and read from input are output in either MGD77 format or as a list.
Required Arguments¶
- NGDC-ids
Can be one or more of five kinds of specifiers:
- 8-character NGDC IDs, e.g., 01010083, JA010010etc., etc.
- 2-character agency codes which will return all cruises from each agency.
- 4-character <agency><vessel> codes, which will return all cruises from those vessels.
- =list, where list is a table with NGDC IDs, one per line.
- If nothing is specified we return all cruises in the data base.
(See mgd77info -L for agency and vessel codes). If no file extension is given then we search for files with one of the four known extensions. The search order (and the extensions) tried is MGD77+ (“.nc”), MGD77T (“.m77t”), MGD77 (“.mgd77” ) and plain text file (“.dat”). Use -I to ignore one or more of these 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 $GMT_SHAREDIR/mgd77].
Optional Arguments¶
- -Hheadervalues.txt
- Obtain header field values from the input text file. Each row of the input file should consist of a header field name and its desired value, separated by a space. See below for a sample header file and for the full list of header field names.
- -Mf[item]|r|r
- List the meta-data (header) 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. For the M77T format, append t instead.
- -V[level] (more …)
- Select verbosity level [c].
- -^ or just -
- Print a short message about the syntax of the command, then exits (NOTE: on Windows just use -).
- -+ or just +
- Print an extensive usage (help) message, including the explanation of any module-specific option (but not the GMT common options), then exits.
- -? or no arguments
- Print a complete usage (help) message, including the explanation of all options, then exits.
Header Item Sample File¶
Format_Acronym MGD77
Source_Institution SOEST - UNIV. OF HAWAII
Country USA
Platform_Name KILO MOANA
Platform_Type_Code 1
Platform_Type SHIP
Names of All MGD77 Header Fields¶
Survey_Identifier
Format_Acronym
Data_Center_File_Number
Parameters_Surveyed_Code
File_Creation_Year
File_Creation_Month
File_Creation_Day
Source_Institution
Country
Platform_Name
Platform_Type_Code
Platform_Type
Chief_Scientist
Project_Cruise_Leg
Funding
Survey_Departure_Year
Survey_Departure_Month
Survey_Departure_Day
Port_of_Departure
Survey_Arrival_Year
Survey_Arrival_Month
Survey_Arrival_Day
Port_of_Arrival
Navigation_Instrumentation
Geodetic_Datum_Position_Determination_Method
Bathymetry_Instrumentation
Bathymetry_Add_Forms_of_Data
Magnetics_Instrumentation
Magnetics_Add_Forms_of_Data
Gravity_Instrumentation
Gravity_Add_Forms_of_Data
Seismic_Instrumentation
Seismic_Data_Formats
Format_Type
Format_Description
Topmost_Latitude
Bottommost_Latitude
Leftmost_Longitude
Rightmost_Longitude
Bathymetry_Digitizing_Rate
Bathymetry_Sampling_Rate
Bathymetry_Assumed_Sound_Velocity
Bathymetry_Datum_Code
Bathymetry_Interpolation_Scheme
Magnetics_Digitizing_Rate
Magnetics_Sampling_Rate
Magnetics_Sensor_Tow_Distance
Magnetics_Sensor_Depth
Magnetics_Sensor_Separation
Magnetics_Ref_Field_Code
Magnetics_Ref_Field
Magnetics_Method_Applying_Res_Field
Gravity_Digitizing_Rate
Gravity_Sampling_Rate
Gravity_Theoretical_Formula_Code
Gravity_Theoretical_Formula
Gravity_Reference_System_Code
Gravity_Reference_System
Gravity_Corrections_Applied
Gravity_Departure_Base_Station
Gravity_Departure_Base_Station_Name
Gravity_Arrival_Base_Station
Gravity_Arrival_Base_Station_Name
Number_of_Ten_Degree_Identifiers
Ten_Degree_Identifier
Additional_Documentation_1
Additional_Documentation_2
Additional_Documentation_3
Additional_Documentation_4
Additional_Documentation_5
Additional_Documentation_6
Additional_Documentation_7
Examples¶
To generate an MGD77 header from A77 input, try
gmt mgd77header km0201 -Hkmheaderitems.txt -Mf > km0201.h77
See Also¶
mgd77info, mgd77list, mgd77manage, mgd77path, mgd77track, x2sys_init
References¶
The Marine Geophysical Data Exchange Format - MGD77, see http://www.ngdc.noaa.gov/mgg/dat/geodas/docs/mgd77.txt.