Enhancing Sonar Performance; Correct Range Setting; Figure 2: Range Setting Diagrams; Figure 3: Range Setting - Too Long - Teledyne SeaBat T Series Operator's Manual

ACTIVE SONAR USAGE
6.2

Enhancing Sonar Performance

6.2.1 Correct Range Setting

Select the appropriate range scale to keep the horizontal bottom image at or above the widest
part of the sonar wedge as visualized in Figure 2:
If the Range is set too short the outer beams will be lost. If the Range is set too long, the results
may be noisy data.
 Diagram A depicts a proper range setting.
 Diagram B depicts an acceptable range setting for a swath that is beginning to fade
due to the effects of signal loss in the outer swath.
 Diagram C depicts an incorrect range setting. Notice that the still-useable ends of the
swath are being cut off by the limits of the range setting.
Note that the range setting affects ping rate: the longer the range, the lower the ping rate and
thus the fewer along-track pings. Higher range settings are required for tilted heads (see also
section 6.3.4 below).
The Range adjusts itself automatically when Tracker is selected (see also section 6.3.2 below).
For additional examples on incorrect range settings and possible solutions, see Table 3.
With the Range set too long, the receivers are "open" for too long and the system is recording long
after the acoustic returns from the seabed have been received. Spurious background noise can
be amplified, especially when TVG is used, and this can give noisier data. The ping rate is also
reduced thereby reducing sounding density. This should not be used to artificially reduce the ping
rate, rather the Range should be set correctly, and the ping rate should be capped using Max rate.
Refer to the RESON Sonar UI User Manual (see Appendix E Reference Documentation.)
SeaBat T-Series Subsea Operator's Manual
Version 7

Figure 2: Range Setting Diagrams

Table 3: Incorrect Range Settings – Examples and Solutions
Figure 3: Range Setting – Too Long
Page 30
NOTE
January 31, 2019