ray turning points to clear Walvis Ridge at about 1700 metres. A total duration of 12 seconds would imply an unobstructed path down to a depth of about 3200 metres.

Since the earliest rays without reflections are not early enougah (to the extent of about 10 seconds) to account for the duration of the arrival waveform, it seems probable that the early arrivals are made up of reflected rays.

Figure 4.　Sound Speed Profile (SSP) and Group speed

Figure 5.　Depth and delay for 4390 Mm path.

Investigation of reflected rays

　

The WHOI Bowlin RAY code (6) can compute reflected rays and provides a number of end results. Figures 6 to 8 show some of the reflected rays as well as profiles of the undersea areas where rays are reflected. The legends for Figures 4 to 6 refer to the delay time, in seconds, compared to the arrival time of the axial ray.

Figure 6.　Eigenrays at the source

BACK　　　CONTENTS　　　NEXT