next up previous contents
Next: plotrth.hlp Up: The BOUNCE reflection Previous: The BOUNCE reflection


BOUNCE computes the reflection coefficient for a stack of acoustic media optionally overlying elastic media. The reflection coefficient is written to a '.IRC' file (internal reflection coefficient). This file can be used by KRAKENC to provide a boundary condition or plotted using PLOTRTH.

The input structure is identical to that used by KRAKENC although the input lines for source and receiver depth are not read and can be omitted. Furthermore, the surface boundary condition is ignored and, in effect, replaced by a homogeneous halfspace where the incident wave propagates.

If you are interested in getting a reflection coefficient for a bottom which is being used in a KRAKENC run you will need to delete the layers corresponding to the water column. Otherwise you will get a reflection coefficient corresponding to a wave incident from above the ocean surface.

The angles used for calculating the reflection coefficient are calculated based on the phase velocity interval [CMIN, CMAX]. For a full 90 degree calculation set CMIN to the lowest speed in the problem (say 1400.0) CMAX to 1.0E9. The actual number of tabulated points is determined by RMAX.

I suggest you pick RMAX equal to 10 km, interrupt BOUNCE after about 5 seconds and look at NKPTS which is displayed in the print file. You can then increase or decrease RMAX to obtain adequate sampling of the reflection loss curve (200 points is probably sufficient).


        Name           Unit         Description
        *.ENV            1       ENVironmental data
        *.BRC           10       Bottom   Refl. Coef.  (optl)
        *.IRC           12       Internal Refl. Coef.  (optl)

        *.PRT            6       PRinT file



'Refl. coef. test problem'
100 0.0 20.0
    0.0 1600.0 400.0 1.8 0.2 0.5
   20.0 /
'A' 0.0
   20.0 1800.0 600.0 2.0 0.1 0.2
1400.0 19000.0
10.0                  ! RMAX (km)
1 50.0 /              ! NSD  SD(1:NSD)
501 0.0 150.0 /       ! NRD  RD(1:NRD)

The above example (taken from the SAFARI reference manual) involves two elastic layers.

Michael B. Porter
Tue Oct 28 13:27:38 PST 1997