Sampling & Aliasing Reference
Concise reference to sampling rate, filtering, aliasing and bandwidth control for measured and analysed shock signals.
Key definitions
- Sampling frequency fs: samples per second
- Nyquist frequency: fs/2
- Aliasing: higher-frequency content folding into a lower apparent frequency
- Anti-alias filter: analogue/digital filtering applied before decimation
- Measurement bandwidth: frequency band over which amplitude/phase are considered trustworthy
Core relationship
fs>2fmax is the mathematical minimum; engineering acquisition normally uses margin.
Use with care
Definitions and notation vary between organisations and standards. Confirm the controlled specification, response quantity, sign convention, damping and units before applying a formula or comparing datasets.