Akkarat Boonpoonga

Fast and efficient detection of buried object for GPR image

The detection and identification of buried objects in GPR images generally involve curve fitting or pattern recognition techniques, which require high computational power and long processing time, e.g., 42 minutes per image. So far, real time detection, which requires fast processing speed, has never been achieved. This paper presents a fast and efficient technique for the detection of buried landmines in the Southern Region of Thailand. The experiment set up consists of five types of soil in the areas with varying numbers and positions of landmines. The detection ratio is high with processing time in the range of 44-240 seconds. To the best of our knowledge, this can be considered as one of the fastest detection technique.

Simple Estimation of Late-Time Response for Radar Target Identification

This paper proposes a conceptual technique for the simple estimation of the late-time response for radar target identification without a priori knowledge of the target geometry or orientation. In the proposed technique, the cross correlation between the backscattering response and transmitted wave is performed. Peaks will occur in the cross-correlation output when the transmitted wave is aligned with the same features in the received backscattering response. The commencement of the late-time response corresponds with the peak resulting from a superimposed pattern between the transmitted wave and late-time response. The matrix pencil method was exploited in order to extract the poles from the received backscattering response. Several simulations were performed to evaluate the performance of the proposed estimation technique. The simulation results confirmed the superiority of the proposed approach. In the special case of the transmission with a monocycle pulse, the commencement of the late-time response can be automatically selected from the third peak of the resulting cross-correlation output.

Radar target identification of coated object using Cauchy method

This paper presents an object identification. The PEC sphere which is coated by different dielectrics is determined through poles extracted by using a Cauchy method. Simulations were conducted to investigate the effect of electrical property and thickness of dielectrics used to coat the PEC sphere. Poles extracted from the scattering frequency response of objects are employed to identify their properties. Simulation results show that different dielectrics and thickness of coating materials have different poles.

Ground penetrating radar (GPR) for counter improvised-explosive devices in Thailand

This paper presents a study on the ground penetrating radar (GPR) for counter improvised-explosive devices in Thailand. In the study, the commercial GPR was used to test a gas tank widely used as a main component of the improvise-explosive device. The test was performed in main two situations that are in an anechoic chamber and on the road. The B-scan images obtained from GPR were analyzed. The recognition technique was developed to detect the improvised-explosive device. The technique is a combination between the regionalization and hyperbolic identification. The results are shown to verify the performance of the proposed technique. Moreover, the A-scan signal at the center of the hyperbolic curve was selected for performing object identification. A short-time matrix pencil method is applied to the system.

On the Resolution Improvement of Radar Target Identification with Filtering Antenna Effects

An investigation on the improvement of the resolution of a radar target identification system is presented in this paper. Degradation of resolution is mainly due to influence factors associated with antennas, including the strong coupling between transmitting and receiving antennas and the variation in the antenna response. A filtering technique was therefore introduced to mitigate the underlying problem. In the technique, the antenna effects were filtered out of the total response backscattered from the objects in the radar target identification system. The short-time matrix pencil method (STMPM) was then employed to extract the poles from the backscattered response in order to identify the object. Simulation and experimentation examples are illustrated to confirm the improvement of the resolution by filtering the antenna effects. The simulation and experimentation were divided into several categories, that is, different antennas and differently shaped objects, in order to validate the advantage of filtering the antenna effects. They were setup in order to demonstrate that the poles obtained from performing the STMPM without the filtering technique were mainly because of the antenna rather than the object’s characteristic. The results showed that the resolution of the identification was significantly increased when performing pole extraction and filtering the antenna effects.

Measurement for radar target identification using short-time matrix pencil method

This paper presents the measurement for radar target identification using a short-time matrix pencil method. Our measurement setup is done in an anechoic chamber to absorb reflections of other electromagnetic waves. Two different target shapes are used to examine the identification. In our measurement, a vector network analyzer is employed to measure the scattering response in term of S21. The scattering response in frequency domain is converted to that in time domain by using the inverse Fourier transform. The short-time matrix pencil method is applied to extract poles from the late-time portion of the scattered transient response. These poles are used to identify the targets. Measurement results show the potential practical application of radar target identification using a short-time matrix pencil method.

FPGA implementation for GPR signal processing based on HW/SW co-design architecture

This paper proposes a field programmable gate array (FPGA) implementation for signal processing of a ground penetrating radar (GPR). The signal processing includes zero offset removal and clutter reduction. The implementation is based on the hardware and software (HW/SW) co-design. The hardware structures are introduced for performing zero offset removal and clutter reduction. The hardware structures are constructed with a basic processing elements such as multipliers and adders etc. Software designed on MicroBlaze is employed to control the hardware architectures and data flows including reading and writing memories. The design architectures including hardware and software is implemented on a Xilinx Zynq-7000 All Programmable SoC XC7Z020-CLG484-1 FPGA device. Experimental results based on the FPGA device are given to examine the performance of the proposed implementation. The B-scan GPR image are shown to demonstrate the ability of the proposed architecture. Preliminary experimentations show good agreement between implementation and simulation.

Effect of soil perturbation on radar identification of buried object using matrix pencil method

This paper presents an analysis of effect of soil perturbation on radar identification. A matrix pencil method is utilized to extract poles from the late-time portion of the scattering transient response of the object. Simulations are conducted to evaluate the effect of soil perturbation on these poles. Simulation results shows the perturbation of soil, especially in term of dielectric constant and object depth, have a strong effect on poles. An appropriate Euclidean distance is introduced to classify the object buried in soil with its different properties.