Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

High-resolution algorithms to estimate the depth of near-surface interface using ground-penetrating radar (GPR) can provide a measurement of thin to thick top layer using synthetic data for surface-coupled antennas. In practice, the air-coupled antenna configuration in the target depth estimation needs to determine the air-gap distance between the antenna module and the surface. In this study, the authors present an improved approach of estimating the antenna height for measuring thin to thick top coal layer using the high-resolution algorithms. In GPR, backscattered echoes are generally correlated in nature. In order to apply high-resolution algorithms, the authors use two improved spatial smoothing techniques for fighting against the correlation between echoes. Here, in the existence of air-coal-shale-clay and air-coal-shale-coal interface, step frequency continuous wave GPR is used to measure the thickness of the coal layer. Simulation results on the antenna height estimation using synthetic data models, full-wave model and plane wave model are shown to assess the estimation algorithm’s effectiveness. © The Institution of Engineering and Technology 2021.

Department of Communication Engineering

School of Electronics Engineering

Vellore Campus

World University root node

IET Science, Measurement and Technology

Impact of GPR antenna height in estimating coal layer thickness using spatial smoothing techniques

In coal mining, thickness of thin coal layer is measured for maintaining a defined coal mining horizon. Researchers working in the geotechnical field for detection and thickness measurement of near surface interface address challenges using recent development in radar signal processing. This paper addresses challenge in measuring thickness of thin coal layer left on mine haulage way roof for mine safety. Here, step frequency continuous wave ground penetrating radar (SFCW GPR) signal processing is given for measuring thickness of thin coal layer in presence of interfaces as coal-shale and coal-shale-clay. We use multiple signal classification (MUSIC) algorithm for detecting the interfaces of dissimilar material. In order to improve the resolving power, MUSIC with spatial smoothing process (SSP) and modified spatial smoothing process (MSSP) are applied. Experimental results on thickness measurement using synthetic data models, full wave model (FWM), plane wave model (PWM) and modified plane wave model (MPWM) are demonstrated to compare the effectiveness of estimation algorithms. © 2017 IEEE.

MRRS 2017 - 2017 IEEE Microwaves, Radar and Remote Sensing Symposium, Proceedings

Thin coal layer thickness estimation using MUSIC algorithm

The coal mining research technology is gaining popularity in terms of thickness measurement of coal mining horizon. The main challenge is to improve a robust sensing method for estimating the coal layer thickness left on mine-haulage way roofs for mine safety. This study addresses this challenge by step frequency continuous wave ground penetrating radar (GPR), whose resolution is dependent on bandwidth. To improve the time resolution of GPR signal, this study adopted four high-resolution algorithms, which are also known as subspace methods, namely, estimation of signal parameter via rotational invariance techniques, multiple-signal classification (MUSIC) algorithm, polynomial version of MUSIC, i.e. root-MUSIC and root-Min-Norm. The performance of all these algorithms is compared with synthetic data generated by the plane wave model and full wave model. The results are presented in terms of resolution power as well as relative root-mean-square error on the estimated thickness. © 2017, The Institution of Engineering and Technology.

Signal processing for coal layer thickness estimation using high-resolution time delay estimation methods

An important factor for the precise interpretation of ground penetrating radar (GPR) records is to know as much as possible about the transmission features of our antennas. The accuracy of the retrieved parameters in the GPR data inversion depends on the accuracy of the GPR external calibration. In this paper we studied the calibration technique for step frequency continuous wave (SFCW) GPR by two different methods namely, calibration by averaging and calibration by using linear transfer function (LTF) model. The SFCW GPR is implemented with the help of a vector network analyzer (VNA: E50715 of Agilent) and 0.8-4.5 GHz single TEM horn antenna. GPR system using their antenna is calibrated several times at different heights over a metal plate. The error in the calibration based on inaccurate antenna height over metal plate. © 2017 IEEE.