In thick desert area, the main frequency of 45-50 Hz is used, about 15-20 Hz higher than the first-time 3D data, and signal to noise ratio and fidelity are sig- nificantly improved.

In the basis of analyzing the character of different linear time-frequency method, a new method of time-frequency filter is developed to improve the signal noise ratio based on the generalized S transform method.

An analysis of the inductive interference mechanism of transmission system in sonic logging tools shows that a lower impedance of the transmission line is favourable for reducing inductive interference and raising signal/noise ratio.

It is shown that the genetic algorithm very favours the inversion without borehole data restric-tion,and the inversion relating to low signal/noise ratio data.

Fast identification of digital amplitude modulation level at low signal-to-noise ratio

Simulation results reveal that the AR scheme with its decision algorithm outperforms the conventional and other modified TR schemes in generalized signal-to-noise ratio (SNR).

The SNR (signal-to-noise ratio) of the vibration signals of a diesel cylinder lid is the highest.

Identification of Discrete Linear Objects with a Large Signal-to-Noise Ratio

Methods for the conversion of image silver nanoparticles into luminescent products were developed; this considerably increased the signal-to-noise ratio of luminescence reading.

The present paper deals with an elementary principle of a new measurement of runoff with very low discharge by means of resistance measuring-flow, and the nonlinear Flow-Voltage relationships with the resistance measuring-flow. A method of linearization handling is provided to make the Measuring-Runoff Flume in a better linear relationship. The analysis of dynamic response charactertics of Resistance Measuring-flow Flume is based on system dynamics theory, as a result, system parameters ωn and ζ are obtained...

The present paper deals with an elementary principle of a new measurement of runoff with very low discharge by means of resistance measuring-flow, and the nonlinear Flow-Voltage relationships with the resistance measuring-flow. A method of linearization handling is provided to make the Measuring-Runoff Flume in a better linear relationship. The analysis of dynamic response charactertics of Resistance Measuring-flow Flume is based on system dynamics theory, as a result, system parameters ωn and ζ are obtained for judging regulating-storage of measuring-flow device' The Measuring-flow Flume has been applied to measure small discharge in the Hydro-logic Runoff Laboratory. As it belongs to instantaneous flow-rate measurement method, the runoff hydrography measured is very clear as regards its duration, peak discharge, lag of time, and relevant parameters. In addition, the device has a higher stability of electronic circuit and better signal-to-noise ratio, and the problem of electolytic action at electrodes surface due to impurity of the water has been solved, so it is more convenient to make research of the rainfall-runoff relationship in laboratory. Finally, in this paper a comparison of cumulative sum of hydrography from Resistance Measuring-flow Flume with cumulative water-volume-method is given, and satisfactory results have been obtained.

The residual static correction plays a very important role in seismic data processing. Toobtain reasonable results,it is necessary to trace the correct reflection zones and to pick ac-curate time shifts between traces. A commonly used method is the correlation method.If the signal-to-noise ratio is relatively low, it is often necessary to choose one more reasonable re-sult from two completely different ones.A wrong choice may seriously distort the seismicprofile. This is the so-called multiple value...

The residual static correction plays a very important role in seismic data processing. Toobtain reasonable results,it is necessary to trace the correct reflection zones and to pick ac-curate time shifts between traces. A commonly used method is the correlation method.If the signal-to-noise ratio is relatively low, it is often necessary to choose one more reasonable re-sult from two completely different ones.A wrong choice may seriously distort the seismicprofile. This is the so-called multiple value problem. Wavelet Packet is a new method of sig-nal processing, It can split a signal into many pieces,with different infomation carried bydifferent pieces. The pure signal may be stored in some special pieces,If this is true,a puresignal can be extracted just by picking out these special pieces. A preprocessing method forseismic data is developed based on the said ideas. Numerical experiments show that the mul-tiple value problem is well solved.

Both the signal/noise ratto improvement of stacked 3-D seismic data and the trace interpolation of cross line have not been nicely achieved yet in present practice. Some data processing centers process in-line and cross-line seismic data respectively in different steps by 2-D polynomial fitting module for signal/noise ratio improvement. With polynomial fitting theory, we simultaneously finish both signal/noise ratio improvement and cross-line trace interpolation of stacked 3-D seismic data(here trace...

Both the signal/noise ratto improvement of stacked 3-D seismic data and the trace interpolation of cross line have not been nicely achieved yet in present practice. Some data processing centers process in-line and cross-line seismic data respectively in different steps by 2-D polynomial fitting module for signal/noise ratio improvement. With polynomial fitting theory, we simultaneously finish both signal/noise ratio improvement and cross-line trace interpolation of stacked 3-D seismic data(here trace interpolation is necessary because its group interval is two times that of in-line. ). Single-step processing can bring CDP seismic data for 3-D migration.This method makes full use of 3-D seismic informations,thus improving data processing efficiency.