Quantization Efficiency
Quantization is a nonlinear process which generates additional frequency components (Thompson et al. 1986). This means that the signal is no longer band-limited, so the sampling theorem no longer holds. If a signal is sampled at the Nyquist frequency, information will be lost. Therefore, sampling faster than the Nyquist frequency results in detection of more of the signal and a lower signal-to-noise ratio [SNR]. Let beta be the oversampling ratio and define
Then the following table gives values of eta_Q for a number of parameters.
The Very Large Array of 27 radio telescopes in Socorro, New Mexico uses three-level quantization at beta=1, so eta_Q=0.81.
See also
OversamplingExplore with Wolfram|Alpha
References
Thompson, A. R.; Moran, J. M.; and Swenson, G. W. Jr. Fig. 8.3 in Interferometry and Synthesis in Radio Astronomy. New York: Wiley, p. 220, 1986.Referenced on Wolfram|Alpha
Quantization EfficiencyCite this as:
Weisstein, Eric W. "Quantization Efficiency." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/QuantizationEfficiency.html