Posts

Unpredictable critters

Unpredictable Critters Last time I wrote a post it was on the introduction of moving receivers in dBSea (link to post).
in this post I want to visit the topic of deciding what paths the moving receivers/animals should take in our scenario.

I start with a few assumptions:
Animals only swim away if the noise is above a certain threshold.Animals swim directly away from the source at all times.Animals have some error in their heading (± 10 degrees), meaning that "2." above will have some random error to it.Animals have a max evasion swmming speed (you're free to complicate things by introducing a dose-response swimming speed!).Noisy vessels move in straight lines.Constants for this post:
The vessel moves at 2.5 m/s (think seismic survey vessel).Vessel source level is 220 dB RMSTranmission loss is given by: TL = 15 x log(range). For impact modelling in these types of surveys it's ofte assumed that the animals will swim perpendicular to the survey line from the moment they s…

Moving with the times

Bending the rules

One size fits all?

Oversampling

Update 2.2 - Focus on getting your data in and out

Importing bathymetry, the basis of your model

A side-on view

dBSea 2.1

Dolphins in Greece

On the bottom

one, one hundred, one thousand or ten thousands?

Catch you on the flip side (of sound) - Updated!