User`s manual

Freq uently Asked Questions (con’t)
What Gain setting should I use?
The Gain setting is like a volume control on a stereo, the higher the number, the
‘louder’ the image will be. The type of seafloor beneath you will determine the gain
setting that you should use. When the Color Table is set to ‘Color’, the sidescan data
will be displayed using blue, green, orange, yellow, white a red colors. Weak returns
will be blue and strong returns will be red. A muddy bottom will be displayed in blue
with a Gain of less than about 16dB. Whereas, a rocky bottom might be red at the same
Gain setting. In this case, you should lower the gain to maybe less than 6dB. The key is
to set the Gain such that only very strong returns show up in the red color. If the Gain is
set too high, most of the image will be saturated with red which limits the dynamic
range of the system, meaning you won’t be able to ‘see’ the difference between a target
lying on the bottom and the bottom itself. Normally, the Gain should be set anywhere
between 6dB and 20dB (but please experiment). Once the gain is set, using the ‘Grey’
Color Table is useful for seeing different shapes on the bottom and shadows will be
more apparent.
When collecting sidescan data, why does the “No Data at COM1” message flash
once and a while when using a Laptop computer?
If any of the laptop’s Power Management settings are enabled (i.e. maximum battery
life, hard drive shut down, etc…), the laptop has to monitor these activities at the same
time that the real time sonar data is being acquired. This can cause the Win881 ss.exe
program to miss data from the SportScan Head and the message might flash. Ensure that
all Power Management settings are disabled in the BIOS settings and through the
Control Panel ‘Power’ settings.