Context
A lower frequency gives you a better detection range because the attenuation loss is smaller. A higher frequency gives you better range resolution. A higher frequency also gives you narrower beams and a "sharper" image".
Noise from internal and external sources have an impact on the choice of operating frequency. One specific frequency may perform better than the others on your vessel. To measure the noise level, observe the value presented on the Noise page in the BITE dialog box.
We recommend that you do this test twice. First, do the test with all other hydroacoustic systems (echo sounders, ADCP, sonars) turned off. Second, do the test with normal operating conditions. This allows you to see how the other hydroacoustic systems affect the operation and performance of your SN90 system.