Converting a continuous signal into discrete samples at fixed intervals.
Sampling measures a continuous signal at intervals T_s=1/f_s, giving x[n]=x(nT_s). Spectrum replicates around multiples of f_s. Ideal impulse sampling vs practical sample-and-hold. Anti-alias filters ensure f_s>2f_max. Reconstruction uses sinc interpolation or DAC with smoothing.
Audio is sampled at 48 kHz in video production.
Sampling converts a continuous signal into numbers, which is the first step in all digital signal processing.
Converting a continuous signal into discrete samples at fixed intervals.
Sampling converts a continuous signal into numbers, which is the first step in all digital signal processing.
The time between successive samples, and its reciprocal is the sampling frequency that sets the highest signal frequency you can capture.
Too slow a rate causes aliasing, which makes high frequencies appear as lower ones, so an anti-alias filter is needed before sampling.
Typical applications include logging a vibration sensor at a fixed rate for analysis, digitising an audio signal for storage and sampling a temperature sensor every second for a control loop.
Study "Filtering concept" first (topic 22 of 101 in Signals, Control & Comms). It covers the groundwork this topic builds on.
Nyquist rate. Oversampling. Sample and hold circuit.
Audio is sampled at 48 kHz in video production.
The next topic is "Aliasing", which builds directly on this one.
It is classed as Beginner in Signals, Control & Comms (topic 23 of 101). It is an entry-level topic. It relies only on basic school mathematics and the ideas introduced earlier in this discipline.
Want to practise? Open the interactive course for quick checks, quizzes, simulations and progress tracking.