Sound velocity correction – Triton BathyPro User Manual

Page 69

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2. Enter a Tide height (in meters) in the top, right-hand box.
3. Click

Next to continue entering tide data pairs, if more pairs are desired.

The system determines the time interval based on the differences
between your entered values of time (or, if you press Next without
entering an additional value, the system sets the interval to five minutes).

4. From the Interpolation model combination box, choose Spline or Linear.

Alternatively, you can import a table of tidal values from an ASCII text file.
The file extension is TID. The tide parameters have the format shown in
Table 3.

TABLE 3. TID tide parameters format

Date

Time

Tide Height

19990111 122815 1.20

19990111 123315 1.21

19990111 123815 1.22

19990111 124315 1.24

Use a space or tab to delimit the columns in the TID file.

Sound Velocity Correction

Clicking the Settings… button to this parameter leads to the Properties for
speed of sound dialog box (Figure 34). From there you can specify (or
import an ASCII file of) a table of sound velocities for different depths in the
survey area. It gives you a way to enter sound corrections for various depths
when you want to compensate for ray-bending of the acoustic beams.

BathyPro uses these velocities to calculate the ray path direction and path
length. Because a change in speed marks the boundary of a layer, each
value is taken as a band of similar velocities, and the refraction of the beam
is calculated for each layer interface. From that data a corrected position
and depth value are calculated for each beam.

June 2004

BathyPro User’s Manual

69

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