1.  NAME

  Variable Names - Convention for specifying CODAS variables

  2.  DESCRIPTION

  This manual page describes the syntax for specifying CODAS database
  variable names within control files. These are required by some
  utilities that access data regardless of the database content.

  Variables must be specified by the name they have in the database.
  They must also be present in it. The name is case sensitive. The list
  of available names for a database can be displayed with showdb.
  Additional variable names which are not listed in the database are:

     TIME
        To access the profile time.

     POSITION
        To access profile position. The returned value will be a two
        element array with both longitude and latitude values.

     LONGITUDE
        To access profile longitude, only.

     LATITUDE
        To access profile latitude, only.

  Note that the names that can be used depend firstly on the producer
  definition file used to create the CODAS database.

  It is not possible to access a whole structure, however each of its
  element can be specified. The syntax is similar to the C programming
  language:

       STRUCTURE_NAME.element_name

  Access is limited to one structure level, i.e. if a structure element
  is a structure itself, you cannot access its values.

  3.  EXAMPLE

  The following examples assume that the CODAS database to access has
  been created together with a producer definition file containing the
  following lines:

  ______________________________________________________________________
    ...

    PROFILE_VAR    8  SHORT     U                    0       1.E-3   m/s
    PROFILE_VAR    9  SHORT     V                    0       1.E-3   m/s
    PROFILE_VAR   54  SHORT     W                    0       1.E-3   m/s
    PROFILE_VAR   68  STRUCT    NAVIGATION           0       1       none
    PROFILE_VAR   69  STRUCT    BOTTOM_TRACK         0       1       none
    ...

    DEFINE_STRUCT  BOTTOM_TRACK  3
      ELEM         1  FLOAT     u                                    m/s
      ELEM         1  FLOAT     v                                    m/s
      ELEM         1  FLOAT     depth                                m

    ...

    DEFINE_STRUCT  NAVIGATION 4
      ELEM         1  DOUBLE   latitude                             deg
      ELEM         1  DOUBLE   longitude                            deg
      ELEM         1  DOUBLE   speed                                knots
      ELEM         1  DOUBLE   course                               deg

    ..

  ______________________________________________________________________

  To access the velocities of an ADCP database, use U, V and W.

  To access the percent good and spectral width of an ADCP database, use
  PERCENT_GOOD and SPECTRAL_WIDTH.

  To access the ship's speed from the navigation, use NAVIGATION.speed.

  To access the bottom tracking velocities, use BOTTOM_TRACK.u and
  BOTTOM_TRACK.v.

  4.  AUTHOR

  Manual page written by Pierre Jaccard, Geophysical Institute,
  University of Bergen, 1999.