Block VI: Noise and Signal Sources

OASI treats 4 types of noise and signal sources simultaneously, depending on the value of the parameters in this block:

SSLEV

Strength in dB of sea surface noise sources. Per definition the source strength corresponds to the acoustic pressure the same source distribution would yield in an infinitely deep ocean [3,12]. The value of SSLEV is interpreted in two different ways, depending on its sign:

SSLEV:

Level in dB of white surface source spectrum.

SSLEV<0:

A negative value identifies a logical unit for a file containing the frequency dependence of the surface source level. The format of the source level files is described in Section 11.1.11.

WNLEV

Level of white noise on sensor in dB. Note that the white noise is added after the sensor gain.

DSLEV

To allow for more horizontal directionality of the noise field than predicted by the surface noise model, an additional, deeper sheet of sources can be introduced.

NDNS

This parameter specifies the number of discrete sources present (targets or interferers).