Simrad ES80 Reference Manual page 413

• Fishing gear noise
A The transducer can pick up noise from
• Biological disturbances
• Interference
• Cavitation
• Propeller noise
• Flow noise
• Acoustic noise from other hydroacoustic systems
The transducer cable is long, and may pick up electric noise from generators,
B
pumps, cooling systems and other electric or electromechanical devices.
The preamplifiers are very sensitive, and they can easily pick up electrical noise
C
from internal and external power supplies. The preamplifiers are also vulnerable for
analogue noise created by their own electronic circuitry. Digital noise created by
the converter and processing circuitry can also create problems.
Converters transform the analogue echoes to digital format.
D
Signal processing circuitry can create digital noise.
E
Details
Select channel
Use the spin box to select which channel to study. In this context, the phrase
channel is used as a common term to identify the combination of transceiver,
transducer and operating frequency.
Noise estimate
For every transmission ("ping") the ES80 measures the echo levels along the
chosen range. Typically, these measurements are made every five meters, even for
long ranges.
All echoes and noise in the water are recorded. This includes noise generated by
your own vessel (electric, propellers, machinery etc), water flow, cavitation and
interference. Echoes from fish and other species, as well as from the bottom, are
detected and added to the equations.
406273/C
Functions and dialog boxes
411