The FIELD program uses the modes calculated by \KRAKEN\

and produces a shade file which contains a sequence of

snapshots of the acoustic field as a function of range and depth.

A snapshot is produced for every source depth specified by the

user.

 

\begin{verbatim}

 

Files:

 

        Name           Unit         Description

Input

        *.FLP            5       FieLd Parameters

        *.MOD          30-99     MODe files

 

Output

        *.PRT            6       PRinT file

        *.SHD           25       SHaDe file

 

---------------------------------------------------------

 

EXAMPLE AND DESCRIPTION OF FLP FILE:

 

/,                               ! TITLE

'RA'                             ! OPT 'X/R', 'C/A'

9999                             ! M  (number of modes to include)

1                                ! NPROF

0.0                              ! RPROF(1:NPROF) (km)

501                              ! NR

200.0  220.0 /                   ! R(1:NR)   (km)

1                                ! NSD

500.0 /                          ! SD(1:NSD)   (m)

1                                ! NRD

2500.0 /                         ! RD(1:NRD)   (m)

1                                ! NRR

0.0 /                            ! RR(1:NRR)   (m)

 

 

 (1) - TITLE

 

       Syntax:

          TITLE

       Description:

          TITLE: Title to be written to the shade file.

                 If you type a /, the title is taken from the

                 first mode file.

 

 (2) - OPTIONS

 

       Syntax:

          OPTION

       Description:

          OPTION(1:1): Source type.

                       'R' point source

                           (cylindrical (R-Z) coordinates)

                       'X' line  source

                           (cartesian   (X-Z) coordinates)

          OPTION(2:2): Selects coupled or adiabatic mode theory.

                       'C' Coupled mode theory.

                       'A' Adiabatic mode theory (default).

          OPTION(4:4): Selects coherent or incoherent mode addition

                       'C' Coherent

                       'I' Incoherent

 

          For a coupled mode run you ***must*** be sure that the

          modes are finely sampled throughout the media

          (excluding the halfspaces if present) so that FIELD can accurately

          calculate the coupling integrals. This is done by using

          a large number of receiver depths (NRD) when you

          do the KRAKEN run. This number should be set to

          give about 10 points/wavelength.

 

 

 (3) - NUMBER OF MODES

       Syntax:

          M

       Description:

          M:    Number of modes to use in the field computation.

                If the number of modes specified exceeds the

                number computed then the program uses all the

                computed modes.

 

 

 (4) - PROFILE RANGES

 

       Syntax:

          NPROF  RPROF(1:NPROF)

       Description:

          NPROF:   The number of profiles, i.e. ranges where a new

                   set of modes is to be used.

          RPROF(): Ranges (km) of each of these profiles.

                   For a range independent problem there is only

                   one profile and its range is arbitrary.

                   mode files must exist for each range of a

                   new profile and be assigned in sequence to

                   units 30,31,... The modes for the last SSP

                   profile are extended in a range-independent

                   fashion to infinity so that RMAX can exceed

                   RPROF(NPROF).

                   *** NOTE: RPROF( 1 ) must be 0.0 ***

 

 

 

 (6) - SOURCE/RECEIVER LOCATIONS

 

       Syntax:

          NR

          R(1:NR)

          NSD

          SD(1:NSD)

          NRD

          RD(1:NRD)

          NRR

          RR(1:NRR)

 

       Description:

          NR:   Number of receiver ranges.

          R():  The receiver ranges (km)

          NSD:  The number of source depths.

          SD(): The source depths (m).

          NRD:  The number of receiver depths.

          RD(): The receiver depths (m).

          NRR:  The number of receiver range-displacements.

                Must equal NRD. (YES, IT IS REDUNDANT)

          RR(): The receiver displacements (m).

                This vector should be all zeros for a perfectly

                vertical array.

 

                The  field is computed by stepping through the

                ranges, R(1:NR), and adding in the range

                displacements, RR() before computing the field

                on the array. Nonzero values are used to tilt or

                distort the receiving array, thereby simulating the

                distortion which occurs on an array deployed in

                the ocean.

 

 

       The format of the source/rcvr info is an integer

       indicating the number of sources (receivers) followed by

       real numbers indicating the depth (range) of each

       receiver.  Since this data is read in using list-directed

       I/O you can type it just about any way you want, e.g. on

       one line or split onto several lines.  Also if your depths

       are equally spaced then you can type just the first and

       last depths followed by a '/' and the intermediate depths

       will be generated automatically.

 

 

\end{verbatim}