Effects of Noise and Absorption on High Frequency Measurements of Acoustic-Backscatter from Fish

Figure 7

The effect of sea thermal noise and receiver noise on SNR for a target with  dB at  m and a beam width 7°. The SNR based on all noises (self-vessel, sea thermal, and receiver noises) is shown by the solid lines for two types of ship with  dB (noise reduced) and 155 dB. The dashed curves indicate the SNR based only on the self-vessel noise; the lower dashed curve is the same as the corresponding curve in the upper left panel of Figure 4.