To avoid interference between the Nortek instruments and any other acoustic instrument, the safest option is always to alternate the sampling regimes. That means, one instrument should sample while the other is in idle mode. If that’s not possible, we recommend the user running a test deployment and analyse the data. In this test deployment, we recommend the user to deploy all acoustic instruments that will also be used in the final deployment, such as Echosounders, Hydrophones, sediment sensors, etc.

Some Nortek instruments are narrow-banded, like the AquaPros and AWACs. For a combination such as an AquaPro HR 2 MHz and AWAC 1 MHz, interference is far less likely to occur. If the combination is an AquaPro HR 2 MHz and one Signature 1000, being the Signature a broad-banded instrument, the interference is more likely to occur. For a combination such as an Aquapro HR and a Vector, where the Vector beams converge to a single point measurement area, if both instruments are spaced out enough, interference is also less likely to occur. To estimate the 3-D space where the diverging Aquapro HR beams will have an influence, consider the instrument head geometry and the distance from the probe. 

Please keep in mind, that even one instrument facing down and another one facing up may interfere with each other’s signal as the signal may not dissipate when it reaches the boundary.

For information on the impact of acoustic instruments on marine life please visit the FAQ Will my ADCP negatively affect marine animals?