Circles Sines and Signals

Abstraction: Interactive tutorial on aliasing and limits of discrete signal interpolation

Key points:

• Discrete signals cannot be naively interpolated; unknown sample points are genuinely unknown — "connecting the dots" is epistemically dishonest
• Aliasing: infinite continuous signals can pass through the same finite set of discrete samples, making them indistinguishable from each other
• Example: flight altitude at 65 minutes is unknown given only 60-minute and 70-minute samples — four visually distinct curves all pass through the same sampled points
• Aliases are signals that look identical after sampling at a given rate, regardless of their actual shape between samples
• This is part of the "Circles Sines and Signals" interactive DSP primer by Jack Schaedler

Connections: Signal Processing · Aliasing · Sampling Theorem · Discrete Signals

Source: https://jackschaedler.github.io/circles-sines-signals/aliasing.html