DragonFly On-Line Manual Pages

X_INIT(1)                    Generic Mapping Tools                   X_INIT(1)

NAME
       x_init - Initialization of Cross-Over Data Bases.

SYNOPSIS
       x_init -I

DESCRIPTION
       The purpose of x_init is to create two key files that will be holding
       all the cross-over information for all the cruises tested. These files
       are called xx_base.b and xx_legs.b, and they will contain data for each
       cross-over and totals for each leg, respectively.  x_init will create
       these two files in the current directory, and write out the fileheader
       with a 1 as the next record number in the case of xx_base.b. NB! Any
       previous files with the same names in the current directory will be
       erased, so use with caution.

       -I     Must be present form initialization to take effect.

BEWARE
       Both files are binary and have fixed record lengths. The formats of the
       files are as follows:

       xx_base.b:
                   Record length = 40 bytes.
                   Rec # 1:       fileheader
                   Rec # 2:       pairheader
                   Next n recs:        crossover-structure
                   Rec  #  n+3:        pairheader etc.
              The fileheader is a 40 byte character string where the last 10
              bytes contains the record number of the last record in the file.
              The pairheader is a 40 byte character string which contains the
              names of the two legs in question and the number of COEs
              generated between them.  The crossover-structure contains all
              the information for one COE, that is lat, lon, time along leg
              values of gravity, magnetics, and bathymetry at the cross-over
              point, the heading of track #1, and the heading of track #2. See
              program listing for more details on formats. The file is
              sequential in that new data are appended at the end of the file.

       xx_legs.b:
                   Record length = 204 bytes.

              Each record contains the complete information for each leg that
              has been checked. The leg-structure contains fields like year of
              cruise, number of internal/external COEs for gravity, magnetics,
              and bathymetry, their means and standard deviations, and the
              best fitting regression lines, i.e., the dc-shifts and drift-
              rates computed from the time/error data points. See program
              listing for complete description of record format.

SEE ALSO
       GMT(1), x_system(1)

REFERENCES
       Wessel, P. XOVER: A Cross-over Error Detector for Track Data, Computers
       & Geosciences, 15, 333-346.

GMT 4.5.14                        1 Nov 2015                         X_INIT(1)