Signal-to-noise ratio (SNR) is a dimensionless quantitative measure that compares the power level of a desired signal to the power level of background noise. It is defined as SNR = P_signal / P_noise, where P denotes average power. In decibels: SNR(dB) = 10·log₁₀(P_signal / P_noise). The parameter that defines SNR is the signal and noise power measurements taken over a defined bandwidth. It persists through mathematical formulas, engineering specifications, instrument readouts, and standardized measurement protocols across communications, audio engineering, imaging, and scientific measurement. [formal: signal-to-noise-ratio | substrate: behavior | horizon: a moment | explicit: yes | epoch: 0.83]
Accepted ontology entry
signal-to-noise-ratio
Signal-to-noise ratio (SNR) is a dimensionless quantitative measure that compares the power level of a desired signal to the power level of background noise. It is defined as SNR = P_signal / P_noise, where P denotes average power. In deci…
Definition
Why it is in scope
The human-made quantitative measure that compares the level of a desired signal to the level of background noise. Built as a dimensionless ratio to characterize signal quality in communications, audio, imaging, and measurement systems. Persists through engineering standards, mathematical definitions, and instrument calibration.
Names and aliases
- signal-to-noise-ratioen · CANONICAL
Relations from this entry
- cmrvhabuj015f2cei72xywgzfSERVES →
SNR is designed and maintained for the sake of analysis — it quantifies signal quality to serve analytical assessment in communications, audio, and measurement. The engineered purpose is to provide a basis for analytical decisions (Law 8d: for whose sake?).
- cmr9uz3vv00elhcxfruyltnd4DEPENDS_ON →
SNR needs measurement to operate now: remove the concept of measurement and SNR has no data to compute — signal power and noise power are both measurement-derived quantities. The removal test passes: no measurement, no SNR operation.
- cmrdu61d40018p7dytt2q2mbyDERIVED_FROM →
SNR is a ratio of signal power to noise power. The concept of power (in physics/engineering) predates SNR by centuries. SNR derives from applying the power concept to compare signal vs noise levels. Which came first? Power measurements and concepts existed long before SNR was formalized.
- cmrsb393a00miollhxpcc7bkzDEPENDS_ON →
SNR is defined as the ratio of signal power to noise power (SNR = P_signal / P_noise). Remove the concept of signal and the ratio loses its numerator — there is no signal to measure, no signal power to compare. The removal test passes: SNR cannot operate without signal as a fundamental operand. Same shape as gain DEPENDS_ON signal (accepted).
- cmrgqx9dq000qyvn12ehpanjuDEPENDS_ON →
SNR is defined as the ratio of signal power to noise power (SNR = P_signal / P_noise). Remove the concept of noise and the ratio loses its denominator — there is no noise to measure, no noise power to compare against. The removal test passes: SNR cannot operate without noise as a fundamental operand. Symmetric to SNR DEPENDS_ON signal.
Relations to this entry
No accepted relations in this direction.
Record identity
- Created
- Aug 12, 2026, 7:56 AM UTC
- Content hash
- 3b5b5b12b202e04ef3f39815ad860c59f8ebf9e177cbc734a33fd6a2b26238db