In GPR imaging, it is common for the depth of investigation to be on the same order as the variability in surface topography. In such cases, migration fails when it is carried out from a datum after application of elevation statics. We introduce a reverse-time migration algorithm where the wavefield...

Surface wave analysis performed on data acquired on purpose or extracted from seismic gathers acquired for body wave surveying is a powerful tool for S-wave velocity model estimation. S-wave velocity is relevant for many engineering applications, but the recent application for hydrocarbon exploration...

Resistivity method is generally considered suitable for investigation of seepage problems in earthen embankments. Construction of a large embankment dam in Taiwan was recently completed, providing a good opportunity for ERT monitoring of the entire water filling process and future performance. The proposed...

Near source time-domain electromagnetic field has the advantages of strong signal, great detection depth, and high accuracy, but according to the traditional transient electromagnetic field theory, the dipole approximation in near source zone will cause a bigger error. To carry out direct time-domain...

In order to grasp the rule of mining transient electromagnetic multi-components characters, numerical modeling methods are employed to simulate the advanced prospecting multi-components response characteristics of gob water with measuring-point arrangement of fanned shape. Results of numerical modeling...

This article is about the study of time domain electromagnetic data migration imaging. First, based on the electromagnetic diffusion theory and the boundary conditions, we deduce the analytical formula of electromagnetic migration field. Then, we complete the calculation of electromagnetic migration...

This article studies the formation, propagation and spatial distribution of the two types of channel wave in three-dimensional space, using three-dimensional inhomogeneous isotropic medium wave equation and solving the elastic wave equation with finite-difference method. Geological model designed in...

The bipolar synchronous sampling method is widely used for noise reduction in Transient Electromagnetic Measurement. However, in practice the ability of this method is not enough to reduce the strong noise from multi-sources. In this paper, we propose an improved method for optimization of the Instrument...

Commonly, TEM data is plotted as apparent resistivity versus time. Later on, with improvement in computer technology, inversion programs have got attention of EM geophysical community. Recently, inversion routines are applied to 1-D problems. In this paper we propose a new approach to interpret SOTEM...

Coal seam seismic survey collapse column is common in heterogeneous geologic bodies. Groud-3D seismic observation due to limitations of its accuracy, for uneven geological subsided column often small leakage test or position error is large, the impact of mining coal mine safety sometimes causing heavy...

Grounded electric source Borehole TEM is introduced in this paper to find the deep conductive ore body, particularly in areas where the ability of surface TEM to define a target is limited either by large depths or by interfering conductive bodies such as overburden shallow sulphides and peripheral mineralized...

With the depth of Coal mining deepen, it becomes a greater challenge to prevent and control water. Quantitative predication on the water abundance of coal seam rapid has become a serious problem. However, since inherent limitations of the method, only qualitative judgments can be done. Based on the numerical...

The traditional optimization inversion method based on iterative method strongly depends on the selection of the initial model, which may easily leads to the local optimal solution, however, the smoke ring inversion has the advantages of fast calculation and no need of initial model. Therefore,the results...

Ray intercept algorithm is the key factor to improve the speed of radio tomography. A second scan search algorithm is proposed to acquire the intersecting point coordinates between ray and gridlines. For this algorithm , successive scanning and sorting of intersection sequence would consume much computing...

The circular loop source is calculated by the method of inscribed polygon inner the circle or numerical calculation. The former uses decomposed polygon in each side with electric dipole, then stack all the electric dipole response; the latter adopts the method of digital filter to calculate the integral...

The lag of water inrush from goaf floor is a great threat to the safety in production, which often leads to a serious property loss. A three-dimensional DC resistivity method,based on the mechanism and the inducing factors of water inrush,is proposed to monitor the possible water inrush accident in this...

Scattering wave imaging method and technique is a new kind of prestack migration. Based on the assumption that the earth subsurface consists of a large number of points (referred to as scatter points), closely located on the interfaces, scattered-waves is formed by single point scattered-wave. Other...

The data acquisition mode of Multi-channel transient electromagnetic method (MTEM) is similar to that of seismic method, it is significant to research pseudo-seismic wave-field extraction technology for MTEM data. Basing on singular value decomposition method and regularized method, we propose correlation...

In normal TEM sounding, the parameter of secondary induced voltage V signal is collected by using magnetic induced coil, however, the late signal is usually too weak to distinguish deep buried target. In this paper, direct measuring of B-field parameters is used to test its practical effect. Firstly,...

A new mine transient electromagnetic method based on U-shape spiral source is proposed. Firstly, the method is introduced. The character of new system is based on a U-shape spiral source which is made up of a U-shape support and the spiral power wire. Furthermore, we analyze the potential advantages...

For the real-time, on-site, direct monitoring of coalfield fire area temperature, we developed a permanent WSN monitoring system with the functions of continuous collection, high temperature detection, remote control, etc. By designing the software and hardware of SPI interface between the JN5139 chip...

The low-resistivity covered layer has shielding effects on transient electromagnetic (TEM) field above prospecting target. The probing depth of TEM depends on observation time. So, it is of great guiding significance to study the estimation method of observation time with low-resistivity covered layer....

Zoeppritz equations can only describe the reflection and transmission of plane waves incident on a single interface. It cannot deal with the thin bed case. The presence of dirt band in thin coalbed makes the problem even more complicated. We present an AVO (amplitude variation with offset) analysis of...

The paper deduced the electrical penetration potential equation of measuring point in point-source current field from the case study of conductive sphere, and proposed the question of the relationship between the response characteristics of electrical penetration curve and spatial location of anomalous...

Acoustic wave equation is an important basis of seismic wave propagation,imaging and migration. Finite difference methods develop with its numerical stability and grid dispersion problems, and the issue of dispersion is a vital above all. Optimization methods can provide a high accuracy within a large...

The coal bed methane (CBM) content is often relatively high where the immediate roof and floor of the coal seam are mudstone. In order to predict the CBM rich region, position of coal seam roof and floor and distribution of sandstone and mudstone are based on acoustic wave impedance inversion and pseudo-acoustic...

we demonstrate how several tools, such as stacking, cross correlation, digital filtering, significantly attenuate the correlated and uncorrelated noise encountered during the estimation of the earth impulse response of multi-transient electromagnetic survey. This study focuses on processing of correlated...

The denoising process is critical when processing transient electromagnetic (TEM) sounding data. For the full waveform PRBS response, an inadequate noise estimation may result in an erroneous interpretation. We consider the Hilbert-huang transform and its application to suppress the noise in the PRBS...

Full waveform inversion (FWI) is an effective inversion method to obtain high resolution and precision seismic imaging. There are a lot of conventional local optimization methods, such as Newton's method and gradient method, to solve the ill-posed nonlinear problem. However, these methods always lead...

In coal exploration, seismic strong reflections from overlying strata may shield the propagation of seismic waves into deep parts, resulting in poor imaging quality for deep targeted area. In fact, seismic wave energy will be lost and velocities will undergo dispersion after passing through viscoelastic...

In order to improve the accuracy of mine transient electromagnetic(MTEM) detection results we carried out field detection experiments for the underground metal interference (tunneling machine, bolt and the anchor net),by analyzing the effects of interference, it turns out that these metallic facilities...

Because the buried hill is deeply buried and seismic data is difficult to identify, it is difficult to exploration the buried hill in Jizhong Depression. Time-frequency electromagnetic method(TFEM)has the characteristics with directly detecting oil and gas reservoirs, and core drilling test and analysis...

The total organic carbon content (TOC) is an important parameter for source rocks evaluation in coal measures. Total organic carbon content determined from logging parameters using back propagation neural network technique, which provide a new method for hydrocarbon source rock evaluation. Use the Turpan...

Taking advantage of the research results of the transmission wave field response in in-seam seismic survey(ISS), and according to the related laws between the L-wave dispersion characteristics and the seam thickness, the technology based on the transmission method of ISS has been developed for quantitative...