uwacan.analysis.convert_to_radiated_noise#
- convert_to_radiated_noise(source, source_depth, mode='iso', power=False)[source]#
Convert a monopole source level to a radiated noise level.
- Parameters:
- source
FrequencyData The source level or source power.
- source_depthfloat
The source depth to use for the conversion.
- modestr, default=”iso”
Which type of conversion to perform
- powerbool, default=False
If the input and output are powers or levels.
- source
Notes
There are several conversion formulas implemented in this function. They are described below with a conversion factor \(F(η)\) such as
\[\begin{split}P_{RNL} = P_{MSL} F(η) \\ η = kd\end{split}\]with \(k\) being the wavenumber and \(d\) being the source depth.
The most commonly used one is the “iso” mode:
\[F = \frac{14 η^2 + 2 η^4}{14 + 2 η^2 + η^4}\]This is designed to convert a monopole source level to radiated noise levels measured at deep waters with hydrophone depression angles of 15°, 30°, and 45°. This has a high-frequency compensation of 2 (+3 dB) and a low-frequency compensation of η^2 (+20 dB/decade).
An alternative is the “average farfield” which averages all depression angles
\[F = 2 / (1 + 1 / η^2)\]This has a high-frequency compensation of 2 (+3 dB) and a low frequency compensation of 2η^2 (+3 dB + 20 dB/decade).
A third one is “isomatch”, which averages up to a depression angle of θ=54.3°, (measured in radians in the formulas below)
\[\begin{split}F = 2 / (1 + 1 / G)\\ G = η^2 (θ - \sin(θ) \cos(θ)) / θ\\\end{split}\]This has the same asymptotical compensations as the “iso” method: high-frequency of 2 (+3 dB) and low-frequency of η^2 (+20 dB/decade).