The ladder, and exactly which rung we are on
Every project like this has a gap between what the model says and what has been demonstrated. Naming the gap precisely is more persuasive than closing it rhetorically.
Nothing has been in water. Every acoustic figure on this site is either measured in air or produced by the model, and is labelled accordingly.
Reached
- 01 Model runsMeasured
The optimiser, physics and DSP execute end to end and produce a parameter set that responds to its inputs.
- 02 Model is defensibleMeasured
Each stage traces to published physics — Mackenzie, Thorp, the active sonar equation — rather than to a fitted curve of our own.
- 03 Signal exists in airMeasured
A synthesised pulse leaves the transducer and is recovered by the receive chain on the bench. Confirms the electronics, not the acoustics.
- 04 Compression measured in airImplemented
Matched-filter output shows the predicted processing gain against a real echo rather than a simulated one.
Not reached
- 05 Signal exists in waterTarget
The same test in a tank. This is where absorption and scattering start behaving like the model says they should — or do not.
- 06 Adaptation demonstrated in waterTarget
Turbidity varied in a tank, and the selected centre frequency observed to move the way the sweep table predicts.
- 07 Range confirmed at depthTarget
Open-water trial against a known target at the required range.
The next rung is the one that matters most and costs least: a tank. It converts the entire water leg of the signal path from modelled to measured, and it is the difference between a claim about turbidity and a demonstration of it.