The sound pulses are transmitted at various
frequencies depending on the application.
Very high frequencies (455 kHz) are used for
greatest definition but the operating depth is
limited. High frequencies (200 kHz) are
commonly used on consumer sonar and
provide a good balance between depth
performance and resolution. Low frequencies
(83 kHz) are typically used to achieve greater
depth capability.
The power output is the amount of energy
generated by the sonar transmitter. It is
commonly measured using two methods:
• Root Mean Square (RMS) measures power
output over the entire transmit cycle.
• Peak to Peak measures power output at the
highest points.
The benefits of increased power output are
the ability to detect smaller targets at greater
distances, ability to overcome noise, better
high speed performance and enhanced depth
capability.
3D Sonar
Your 900 Series™ Fishing System
uses a six-element transducer that
transmits at 455 kHz and is capable
of reaching depths of 240 ft (75 m).
Each transmitted beam is 16 degrees
in width and is symmetrical. The six
beams are lined up next to each
other to provide a total coverage of
53 degrees from side to side, and 16
degrees from front to back. Using
multiple narrow beams together
gives you a wide area of coverage for terrain interpretation and fish location,
without sacrificing the detail only a narrow beam can provide. Your 900
Series™ Fishing System gathers information from a continuous series of
these returned signals. It then interprets this information to create a detailed
3-dimensional view of the terrain passing beneath your boat as you travel
across the water.
2D Sonar
Your 900 Series™ Fishing System also has the capability of displaying
traditional 2-dimensional sonar information from either a 455 kHz beam or
an 83 kHz beam. The 455 kHz single beam has the advantage of providing
increased sonar resolution but is limited to a depth capability of 240 ft
(75 m). The 83 kHz single beam sonar has the advantage of providing sonar
information to 1000 ft (330 m) but the sonar resolution is not as great as with
the 455 kHz single beam.
2
