Signal Recovery from Noise in Electronic Instrumentation
Covering all aspects of the subject, Signal Recovery from Noise in Electronic Instrumentation, Second Edition examines the interference involved with instruments that employ electronic techniques to measure physical quantities, including random fluctuations from thermal or background sources and systematic signal drift or offset. In the case of random noise, the book fully analyzes 1/f as well as white noise. It also discusses the theory and practice of baseline correction, low-pass filtering, multiple time averaging, and phase-sensitive detection. The author explores the best way of measuring the amplitude or the time of occurrence of a signal of known shape. New to this edition are an additional chapter, frequency measurement, and tutorial questions with answers to test understanding of the subject matter. This book will be indispensable to advanced electronics undergraduates, nonspecialist postgraduates using electronic instrumentation, and applied scientists.
Table of Contents
Low-pass filtering and visual averaging: Overview. Low-pass filtering of shot noise. Visual averaging. Baseline subtraction. Multiple time averaging and drift: Multiple time averaging methods. Drift. Multiple time averaging by oscilloscope. Multiple time averaging by computer. Phase-sensitive detector methods: Adaptation of resistor bridge strain gauge. AC coupled amplifier. Drift rejection of PSD. White noise error. Miscellaneous applications. Spectral view of signal recovery: General method. Spectral noise component. Pulse spectrum. Dependence of white noise amplitude upon bandwidth. Noise waveform. Spectral and time-domain views of signal pulse recovery. Shot noise amplitude. Thermal noise amplitude. 1/f noise: General properties. Measurement time independence. Response to combined 'noise'. Experimental result. Frequency response calculations. Low-pass filter. Running average. Visual averaging. Baseline offset correction. Sloping baseline correction. Step measurement. Spatial frequency components of 1/f noise. Frequency response of multiple time averaging. Frequency-domain view of the phase-sensitive detector: Analogue multiplier PSD. White noise error. Reversing PSD. Chopping PSD. Compromise arrangements. PSD imperfections. Non-phase-sensitive detectors. Recovery of a signal submerged in noise. Digitisation and noise: Additional noise due to digitisation. Analogue-to-digital converters. Suitability of real ADC circuits for taking average samples. Point sampling gate. Aliasing. Magnitude determination for transient signals of known shape and timing: Flash spectrometer. Limit setting. Weighted pulse sampling. Matched filtering. Boxcar sampling gate. Offset, drift and 1/f noise. Peak and valley detectors. Software realisation of weighted pulse sampling. Measurement of the time of occurrence of a signal transient: Method for timing a transient with minimum white noise error. Signal pulse timing. Signal step timing. Comparison of the step and pulse methods. Offset, drift and 1/f noise. Lock-in amplifier. Autocorrelation methods. Frequency measurement: Periodic transients of fixed width. Ratemeter. Phase-locked loop. Periodic transients of width proportional to period. Frequency tracker. Single transients. Correlation matching. Noise-optimised averaging of frequency measurements. Frequency domain methods. Appendix: Fourier analysis. Tutorial questions. Answers to tutorial questions. Index.
"Answering a genuine need, Wilmshurst's book is the single most illuminating contribution to and understanding of the range of techniques for efficient signal recovery from electronic noise. It stands apart from the other books and articles by virtue of the originality, clarity, and systematic exposition of every aspect of enhancing an electrical signal. It is an exceptional achievement, written in an outstandingly refreshing manner that should alter the ways in which electronic instrumentation is understood and taught at advanced undergraduate or graduate level and beyond. In short, anyone wanting the ins and outs of signal retrieval should get a copy."
-Current Engineering Practice
"… this is an excellent book."
-Australian & New Zealand Physicist
"… written in a clear and concise style …"
-Journal of Sound & Vibration