Environment
The Environment heading in the Numerical information field contains information related to the environment for the relevant echogram channel.
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Description
•  Sound Speed
This is the sound speed calculated by the ME70.
•  Absorption
The absorption curve is drawn based on the calculations made by the ME70.
•  Noise Estimate
This value reflects an estimation of the noise level over the transducer bandwidth. For every transmission ("ping") the ME70 measures the echo levels along the chosen range. Typically, these measurements are made every five meters, even for long ranges.
•  Equivalent ambient noise
The noise estimate provided by the ME70 includes all noises. This includes noise generated by your own vessel, for example electric noise, propellers, machinery and mechanical vibrations. By means of additional equations, the noise values are compensated for the bandwidth. The equivalent ambient noise value attempts to present the total noise as if it was all from ambient sources.