Adding Decibels

1. Adding Decibels

2. Speed of Sound in Water Medium Effects: Elasticity and Density Variable Effects of: Salinity Pressure Temperature Salinity Temperature Pressure Depth Depth Depth

3. Speed of Sound Factors • Temperature • Pressure or Depth • Salinity

4. Temperature, Pressure, and Salinity

5. Class Sound Speed Data

6. More Curve Fitting Chen and Millero Leroy

7. Expendable Bathythermograph Canister Loading Breech Canister Loading Breech Launcher Recorder Cable (4-wire shielded) Stantion LAUNCHER Optional Equipment Alternating Current PowerCable (3-wire) Terminal Board Depth/Temperature Chart RECORDER Wire Spool Thermistor PROBE (XBT)

8. Typical Deep Ocean Sound Velocity Profile (SVP) Sonic Layer Depth (LD) P T C Deep Sound Channel Axis

9. Refraction High c1 B A D E Low c2

10. c1 c2 c3 c4 1 2 3 4 d e p th 1 2 3 4 1 2 3 4 1 2 3 4 Multiple Boundary Layers where c1 < c2 < c3 < c4 and 1 > 2 > 3 > 4

11. Simple Ray Theory c (c1,z1) (c,z) Snell’s Law z

12. x2 x1 R c1 z1 q1 c2 z2 q2 Positive gradient, g Ray Theory Geometry

13. The z (Depth) and x (Range) Directions csurface=1500 m/s z I=20 x

14. The z (Depth) and x(Range) Directions csurface=1500 m/s z I=20 x

15. x2 x1 q1 R c1 z1 q1 z2 c2 q2 Positive gradient, g Why is R = Radius?

16. x2 x1 R c1 z1 q1 z2 c2 q2 Positive gradient, g Summary

17. Negative Gradient x1 x2 c2 z2 q2 q1 z1 c1 R Negative gradient, g

18. 1 c1 2 0 c2 c0 Example 1 • Given: c1 = 964 m/s, c2 = 1299 m/s, q2 = 30o Dz(between 1 and 0) = 3000m • Find: q1, co, g (between pt 1 and 0), R

19. csurface=1500 m/s I=20 II=30 c100 m=1510 m/s Example 2 • Find gradient, g • Find Radius of Curvature, R, for each ray. • Skip distance – i.e. the distance until the ray hits the surface again • Max depth reached by each ray

20. Backups

22. Slope = tanq x1 x2 z1 z2