scholarly journals A generalisation of the study of sum and square law signal processors with multiple clipped inputs

1976 ◽  
Vol 19 (3) ◽  
pp. 294-315 ◽  
Author(s):  
R. G. Keats ◽  
V. K-K. Yu
Keyword(s):  
Recent Work ◽  
Input Signal ◽  
Signal To Noise Ratio ◽  
Statistical Properties ◽  
Signal To Noise ◽  
Noise Ratio ◽  
Signal Processors

AbstractThe recent work of Cheng and Stokes on the processing of clipped signals from two or three receivers is extended and generalised by removing a number of restrictions. In particular, there is no restriction on the number of receivers and the restrictions on the statistical properties of the signal and noise processes have been considerably relaxed.Mathematically—Plackett's result is used to expand the orthant proabilities involved in increasing powers of the input signal to noise ratio.

TRAVELING SIGNAL‐TO‐NOISE RATIO AND SIGNAL POWER ESTIMATES

Geophysics ◽  
1967 ◽  
Vol 32 (3) ◽  
pp. 485-493 ◽  
Author(s):  
S. M. Simpson
Keyword(s):  
Seismic Noise ◽  
Signal To Noise Ratio ◽  
Signal Strength ◽  
Noise Removal ◽  
Statistical Properties ◽  
Signal Power ◽  
Signal To Noise ◽  
Direct Estimation ◽  
Noise Ratio

Undesirable seismic noise of a nondeterministic type must be destroyed by making use of its statistical properties. Averaging of one sort or another provides methods for performing this noise removal. Our purpose here is to present a method for direct estimation of signal strength versus seismogram time, with stepout as a parameter. After describing the method and its expected behavior to some extent, we illustrate its application to a set of three noisy records.

Statistical properties of estimates of signal-to-noise ratio and number of scatterers per resolution cell

1997 ◽  
Vol 102 (1) ◽  
pp. 635-641 ◽  
Author(s):  
Keith A. Wear ◽  
Robert F. Wagner ◽  
David G. Brown ◽  
Michael F. Insana
Keyword(s):  
Signal To Noise Ratio ◽  
Statistical Properties ◽  
Signal To Noise ◽  
Noise Ratio ◽  
Resolution Cell

Determination of the Best Emulsion for the Microscopy of Crystals

1981 ◽  
Vol 39 ◽  
pp. 32-33
Author(s):  
David A. Grano ◽  
Kenneth H. Downing
Keyword(s):  
Spatial Frequency ◽  
Information Transfer ◽  
Signal To Noise Ratio ◽  
Experimental Situation ◽  
Photographic Emulsion ◽  
Modulation Transfer ◽  
Signal To Noise ◽  
Frequency Space ◽  
Noise Ratio

The retrieval of high-resolution information from images of biological crystals depends, in part, on the use of the correct photographic emulsion. We have been investigating the information transfer properties of twelve emulsions with a view toward 1) characterizing the emulsions by a few, measurable quantities, and 2) identifying the “best” emulsion of those we have studied for use in any given experimental situation. Because our interests lie in the examination of crystalline specimens, we've chosen to evaluate an emulsion's signal-to-noise ratio (SNR) as a function of spatial frequency and use this as our critereon for determining the best emulsion.The signal-to-noise ratio in frequency space depends on several factors. First, the signal depends on the speed of the emulsion and its modulation transfer function (MTF). By procedures outlined in, MTF's have been found for all the emulsions tested and can be fit by an analytic expression 1/(1+(S/S0)2). Figure 1 shows the experimental data and fitted curve for an emulsion with a better than average MTF. A single parameter, the spatial frequency at which the transfer falls to 50% (S0), characterizes this curve.

Experiments in Bright-Field Imaging with Hollow-Cone Illumination

1981 ◽  
Vol 39 ◽  
pp. 226-227
Author(s):  
W. Kunath ◽  
K. Weiss ◽  
E. Zeitler
Keyword(s):  
Signal To Noise Ratio ◽  
Carbon Support ◽  
Electronic System ◽  
Optic Axis ◽  
Hollow Cone ◽  
Signal To Noise ◽  
Bright Field ◽  
Noise Ratio ◽  
Single Field ◽  
Field Imaging

Bright-field images taken with axial illumination show spurious high contrast patterns which obscure details smaller than 15 ° Hollow-cone illumination (HCI), however, reduces this disturbing granulation by statistical superposition and thus improves the signal-to-noise ratio. In this presentation we report on experiments aimed at selecting the proper amount of tilt and defocus for improvement of the signal-to-noise ratio by means of direct observation of the electron images on a TV monitor.Hollow-cone illumination is implemented in our microscope (single field condenser objective, Cs = .5 mm) by an electronic system which rotates the tilted beam about the optic axis. At low rates of revolution (one turn per second or so) a circular motion of the usual granulation in the image of a carbon support film can be observed on the TV monitor. The size of the granular structures and the radius of their orbits depend on both the conical tilt and defocus.

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