The FIELDS program uses the Green's functions calculated by SCOOTER or SPARC and produces a shade file that contains a sequence of snapshots of the acoustic field as a function of range and depth. Alternatively, if a single source/receiver combination is specified then FIELDS produces a plot directly of the Green's function and transmission loss.
Files:
Name Unit Description
Input
*.FLP 1 FieLd Parameters
*.GRN 20 GReen's function
Output
*.PRT 6 PRinT file
*.SHD 25 SHaDe file
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EXAMPLE AND DESCRIPTION OF FLP FILE:
'RDB' ! 'R/X (coord), Lin/DB, Pos/Neg/Both'
200.0 220.0 501 ! RMIN, RMAX, NR
(1) - OPTIONS
Syntax:
OPT
Description:
OPT(1:1): Coordinates
'R' Cylindrical (R-Z) coordinates.
'X' Cartesian (X-Z) coordinates.
OPT(2:2): Scale
'D' dB
'L' linear
OPT(3:3): Spectrum
'P' Positive (recommended)
'N' Negative
'B' Both positive and negative
The spectral integral should formally be done
from all along the real k-axis, however the
negative portion contributes significantly
only in the near-field. Run-time is less
if it is neglected.
OPT(4:4): Interpolation type
'O' POlynomial (for broadband runs)
'A' PAde (for CW runs)
(2) - RECEIVER RANGES
Syntax: RMIN RMAX NR
Description:
RMIN: First receiver range (km)
RD: Last receiver range (km)
NR: Minimum number of receiver ranges
The actual number of ranges used is increased
slightly to satisfy FFT sampling requirements.