Theory#

Why sidescan imagery looks the way it does. Each page takes one idea: it states the physics, with the formula and a diagram, then measures the idea on a real, openly licensed recording, so every number can be checked.

The Examples show how to do a task with sidescanpy; these pages explain the physics behind the steps.

Every page is a script in examples/theory/ that runs when this site is built, on the recordings listed in Example data. Run one yourself with an output directory:

python examples/theory/plot_shadow_height.py out/

How sidescan sees

How sidescan sees

Echo amplitude and decibels

Echo amplitude and decibels

How far a sidescan sees

How far a sidescan sees

Frequency, range and resolution

Frequency, range and resolution

The sonar equation and time-varying gain

The sonar equation and time-varying gain

From slant range to ground range

From slant range to ground range

Slopes, relief and layover

Slopes, relief and layover

A wreck’s height from its shadow

A wreck's height from its shadow

Ping spacing, footprint and coverage

Ping spacing, footprint and coverage

Towfish attitude: pitch, roll and yaw

Towfish attitude: pitch, roll and yaw

Where the towfish is: navigation and layback

Where the towfish is: navigation and layback

Common sidescan artifacts

Common sidescan artifacts