Garmin GPSMAP 9000 Series, Руководство пользователя

Страница: 107 / 232

Sonar Frequencies
NOTE: The frequencies available depend on the transducers being used.
Adjusting the frequency helps adapt the sonar for your particular goals and the present depth of the water.
Higher frequencies use narrow beam widths, and are better for high-speed operation and rough sea conditions.
Bottom definition and thermocline definition can be better when using a higher frequency.
Lower frequencies use wider beam widths, which can let the fisherman see more targets, but could also
generate more surface noise and reduce bottom signal continuity during rough sea conditions. Wider beam
widths generate larger arches for fish target returns, making them ideal for locating fish. Wider beam widths
also perform better in deep water, because the lower frequency has better deep water penetration.
CHIRP frequencies allow you to sweep each pulse through a range of frequencies, resulting in better target
separation in deep water. CHIRP can be used to distinctly identify targets, like individual fish in a school, and
for deep water applications. CHIRP generally performs better than single frequency applications. Because some
fish targets may show up better using a fixed frequency, you should consider your goals and water conditions
when using CHIRP frequencies.
Some transducers also provide the ability to customize preset frequencies for each transducer element, which
enables you to change the frequency quickly using the presets as the water and your goals change.
Viewing two frequencies concurrently using the split-frequency view allows you to see deeper with the lower
frequency return and, at the same time, see more detail from the higher frequency return.
NOTICE
Always be aware of local regulations on sonar frequencies. For example, to protect orca whale pods, you might
be prohibited from using frequencies between 50 to 80 khz within
1
/
2
mile of an orca whale pod. It is your
responsibility to use the device in compliance with all applicable laws and ordinances.
Selecting the Transducer Frequency
NOTE: You cannot adjust the frequency for all sonar views and transducers.
You can select which frequencies appear on the sonar screen.
NOTICE
Always be aware of local regulations on sonar frequencies. For example, to protect orca whale pods, you might
be prohibited from using frequencies between 50 to 80 khz within ½ mile of an orca whale pod. It is your
responsibility to use the device in compliance with all applicable laws and ordinances.
1 From a sonar view, select Options > Frequency.
2 Select a frequency suited to your needs and water depth.
For more information on frequencies, see Sonar Frequencies, page 93 .
Creating a Frequency Preset
NOTE: Not available with all transducers.
You can create a preset to save a specific sonar frequency, which allows you to change frequencies quickly.
1 From a sonar view, select Options > Frequency.
2 Select Manage Frequencies > New Preset.
3 Enter a frequency.
Sonar Fishfinder 93