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Data Processing in Data Acquisition. CDA 4170 - Data Acquisition and Control Systems Janusz Zalewski.
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Data Processing in Data Acquisition CDA 4170 - Data Acquisition and Control Systems Janusz Zalewski
There are two essential components of the data acquisition and control process: data IN and data OUT.Data IN are the measurement data.What we are concerned of about data IN is their accuracy. The accuraccy of the measurements is primarily affected by noise.
Noise is a collective name for various factors affecting negatively the measurements,including:- interfering signals- drift- device noise.
How to account for noise?One has to evaluate its two parameters: amplitude and frequency.
One important and quantifiable source of noise is Quantization Noise, which results from the finite discretization of analog signals.Example. 12-bit ADC converter digitizing a +/-10V signal.
Noise filtering:1) Hardware Filtering – cutting high frequencies2) Nyquist Theorem3) Software Filters – Savitzky & Golay4) Fourier Transform
Sampling Rate TheoremA periodic signal has to sampledat least twice per its period to fully determine its value.
Spectral Analysis of Signals belongs to the Communication Theory and is lectured at FGCU in the “Signals and Systems” course.
Conclusion- That’s about Data IN. How about Data OUT?- This is the subject of the next Module.