Specifications

BATS AND PORTABLE BATS OPERATION
3-55
USBL  Acoustic Data
Brings up Acoustics Data dialog box.
(Same as Acoustic Data in Project Tree)
This data is used within Trackman to
correct positional data based on the
acoustic parameters. Enter the average
water column Speed of Sound in me-
ters/ second or feet/ second or click the
Use Sound Velocity (SV) Profile check
box to enter in the profile or import a
file containing the profile. The default
value is 1500 m/s. The slant range is
calculated using this value and the
acoustic travel time. Enter the Water
Salinity at the hydrophone in part per
thousand. Default is 35 ppt. The TrackPoint hydrophone measures the temperature automatically.
This box should be checked. If not available then a manual temperature at the hydrophone can be
entered in degrees Celsius or Fahrenheit.
NOTE: When WATER TEMP-AUTO mode is selected the system only updates water temperature
upon receipt of a valid acoustic signal.
NOTE: The WATER TEMPERATURE and SALINITY parameters do not affect speed of sound cal-
culations. It is used for phase correction (depression angle) at the water / hydrophone
interface.
Sound Velocity Profile
A single velocity profile can be entered by hand or loaded from a file. At each depth there is a
sound velocity value. The data is being assumed to represent the sound velocity layers for the en-
tire region within which you are operating. Therefore, it is assumed that there is no effect on bear-
ing in this model. A non-direct sound wave segment could not be re-directed to the receive point
(from a bearing point-of-view) since the effect is only on z-axis. The only two parameters that re-
quire correction are the slant-range (SR) and depression angle (DA).
If the SVP data is available in a printout then manually enter the data within the Sound Velocity
Profile chart below. For example, in layer #1 enter in the Depth and the Velocity associated with
that layer. Continue entering data, filling in the chart down to the depth required. If the data en-
tered for the Velocity is between 1400 and 1700 then it is assumed the data is in meters/second. If
the Velocity values are between 4592 and 5576 then the data is assumed to be in feet/second.
The data entered will be shown in the corresponding Graph. The data entered will be saved as a
csv file under the current Jobs folder. For example, ..\Jobs\TP3\CurrentSvp.csv.