PLOTTLR sums the modes to produces plots of coherent transmission loss versus range.
Files: Name Unit Description Input *.PLP 1 PLot Parameters *.MOD 30-99 MODe files Output *.PRT 6 PRinT file --------------------------------------------------------- EXAMPLE AND DESCRIPTION OF PLP FILE: 'RAN' ! OPT (cart, cylin or scaled coords) 999 ! M (number of modes to include) 1, 0.0 ! NPROF RPROF(1:NPROF) (km) 25.0 25.0 ! SD RD (m) 0.0 100.0 501 10.0 10.0 ! RMIN RMAX NR RINC (km) RAXL (cm) 70.0 110.0 10.0 6.0 ! TLMIN TLMAX TLINC (dB) TLAXL (cm) 0.0 ! 3dB smoothing window (m) (1) - OPTIONS Syntax: OPTION Description: OPTION(1:1): Source type. 'R' point source. (cylindrical or R-Z coordinates) 'X' line source. (cartesian or X-Z coordinates) OPTION(2:2): Selects coupled mode or adiabatic mode theory 'C' for Coupled mode theory. 'A' for Adiabatic mode theory (default). For a coupled mode run you ***must*** be sure that the modes are finely sampled throughout the water column 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. OPTION(3:3): Component '' (null) for pressure. 'H' for Horizontal displacement. 'V' for Vertical displacement. 'T' for Tangential stress. 'N' for Normal stress. (2) - NUMBER OF MODES Syntax: M Description: M: Number of modes to use in the field computation. If this number is larger than the actual number of modes in the mode file it is reduced accordingly. (3) - 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). (4) - SOURCE/RECEIVER DEPTHS Syntax: SD RD Description: SD: Source depth (m). RD: Receiver depth (m). (5) - RECEIVER RANGES/AXIS INFO Syntax: RMIN RMAX NR RINC RAXL Description: RMIN: First receiver range (km). RD: Last receiver range (km). NR: Number of receiver ranges. RINC: Range interval for tick marks (km). RAXL: Range axis length (cm). (6) - TRANSMISSION LOSS AXIS INFO Syntax: TLMIN TLMAX TLINC TLAXL Description: TLMIN: TL minimum (dB). TLMAX: TL maximum (dB). TLINC: TL interval for tick marks (dB). TLAXL: TL axis length (cm). If you set TLMIN=TLMAX then the curve is autoscaled. (7) - SMOOTHING WINDOW Syntax: DR3DB Description: DR3DB: Three dB smoothing window (m). The tranmission loss is computed then smoothed in range using a Gaussian filter. DR3DB gives the range interval over which the smoothing is performed.
Figure: Sample output of PLOTTLR: transmission loss vs. range for the Arctic problem.