Edgetech USBL BROADBAND ACOUSTIC TRACKING SYSTEM, User Hardware Manual, Page: 67 / 102

3-21
c. The hydrophone's distance along the Y-axis, forward of the pitch / roll center, is a positive
value. In
F
IGURE
3-15 , the hydrophone is aft of the pitch / roll center, and the Y offset is -10
meters.
2. Enter the offsets at the TrackMan and observe the display to verify that the hydrophone is being
off-set in the proper directions.
F
IGURE
3-15
illustrates the tracking window display as the X and Y
offsets determined above are entered.
a. The hydrophone is represented in the tracking window by a small H. The H shifts to the right
along the X-axis when the positive X offset (7 meters) is entered. The H moves down, parallel
to the Y-axis, when the negative Y offset (-10 meters) is entered.
b. The target continues to be tracked and now displays X and Y data in relation to the pitch / roll
center of the vessel.
3. Hydrophone Depth is the depth of the hydrophone below the surface of the water, refer to F
IGURE
3-15 . Depth is entered as a positive value.
a. The BATS is ready for operation when the hydrophone is in position and the necessary offsets
have been determined, and the acoustic sources to be tracked are active and in the water.
NOTE: If the pinger is at a Depression Angle of less than 20 ° , the
measured Depression Angle and, therefore, the Horizontal Range of the
beacon are impossible to measure accurately. Consequently, the bearing
of the source, relative to some offset position, is impossible to determine.
If this combination of circumstances occurs (pinger; Depression Angle
less than 20
° ; and hydrophone offsets entered), BATS ignores the entered
X and Y offsets so that it can display a correct bearing relative to the
hydrophone. Refer to TrackMan Manual – 0019630 – Section 5:
Troubleshooting, error code 51, which is also included below.
3.3.3 Error Code 51
Pinger Only: Pinger's position can no longer be calculated; refer to bearing value as an position indicator.
Applies only when hydrophone offsets are entered and tracking a pinger when depression angle is < 20°
from horizontal. Purpose of Error 51 is to notify computer system, via RS-232, that all ranges and X or Y
coordinates to that target are minimum values and generally do not indicate actual ranges, so use data
cautiously. At small depression angles (>20° from horizontal), measurement of depression and
subsequent calculation of horizontal range is highly inaccurate. As a result, X and Y hydrophone offsets
are ignored for pinger only, and bearing is displayed relative to actual hydrophone location (& North with
enabled compass). Actual range cannot be computed. Warning applies to individual target only. When
pinger depression angle is < 20° from horizontal, pinger’s position cannot be determined. TrackPoint
shows bearing accurately with respect to hydrophone and places pinger off-screen along with trailing
dotted line. Transponder position remains with respect to reference point.