• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.12
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• pp.1460-1466
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• 2010

In this paper, we analyzed the performance of radar target classification using the monostatic and bistatic radar cross section(RCS) for four different wire targets. Short time Fourier transform(STFT) and continuous wavelet transform (CWT) were used for feature extraction from the monostatic RCS and the bistatic RCS of each target, and a multi-layered perceptron(MLP) neural network was used as a classifier. Results show that CWT yields better performance than STFT for both the monostatic RCS and the bistatic RCS. And, when STFT was used, the performance of the bistatic RCS was slightly better than that of the monostatic RCS. However, when CWT was used, the performance of the monostatic RCS was slightly better than that of the bistatic RCS. Resultingly, it is proven that bistatic RCS is a good cadndidate for application to radar target classification in combination with a monostatic RCS.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.4
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• pp.443-452
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• 2016

Current low-altitude radar system often fails to detect small unmanned aerial vehicles (UAV) because of their small radar cross section (RCS) compared with larger targets. As a potential alternative, a passive bistatic radar system has been considered. We study an optimal deployment problem for the passive bistatic radar system. We model this problem as a covering problem, and develop an integer programming model. The objective of the model is to maximize coverage of a passive bistatic radar system. Our model takes into account factors specific to a bistatic radar system, including bistatic RCS and transmitter-receiver pair coverage. Considering bistatic RCS instead of constant RCS is important because the slight difference of RCS value for small UAVs could significantly influence the detection probability. The paired radar coverage is defined by using the concept of gradual coverage and cooperative coverage to represent a realistic environment.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.5
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• pp.789-798
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• 2021

In this study, for the purpose of collecting and analyzing target-specific RCS data of target signals simulator for verification/improvement of radar system performance, VHF band monostatic/bistatic RCS of civil aircraft(B-747, B-737) and fighter(F-16) models were analyzed by EM simulation tool. In order to reduce the RCS analysis time, the analysis time and RCS data were compared and cross-verified. Also, the analysis range was selected by examining the interpolation error according to the analysis angle resolution. The RCS data obtained for each model were analyzed separately by the incident/reflection elevation angle and frequency. The RCS characteristics according to the shape of the aircraft and the incident/reflection azimuth angle were described. Finally, the statistical RCS distribution value of each model is presented through RCS distribution histogram analysis. In the future, the RCS database obtained by this study will be used for the target signals simulator of the VHF band radar system.

• Journal of IKEEE
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• v.19 no.4
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• pp.566-572
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• 2015

In this paper, we calculate monostatic RCS(Radar Cross Section) and bistatic RCS for improving the Performance of the skin tracking of KSLV-II and the results were compared. EM(Electromagnetic) simulator was used for numerical analysis. For the two paths(L, S), after the vehicle was launched, RCS was calculated for region from 280 to 400 seconds. In the case of using the bistatic radar system, when the vehicle was launched to the L path, tracking performance was better when we receive RCS in Jeju than in Goheung. When the vehicle was launched to the S path, tracking performance was better when we receive RCS in Goheung than in Jeju. In the case of using the monostatic radar system, when the vehicle was launched to the L path, tracking performance was better when we receive RCS in Goheung than in Jeju. When the vehicle was launched to the S path, tracking performance was better when we receive RCS in Jeju than in Goheung.

• Journal of Advanced Navigation Technology
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• v.25 no.1
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• pp.90-95
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• 2021

In this paper, the design method for a high-sensitivity compact resonator for chipless RFID tags is proposed. Proposed high-sensitivity compact resonator uses an interdigital-capacitor structure instead of a capacitor-shaped strip structure in a conventional ELC resonator. The length of the electrode plate of the IDC structure is longer than that of the conventional capacitor-shaped structure, resulting in a larger equivalent capacitance of the resonator. This can lower the resonant peak frequency of the RCS characteristic. Two resonators with the same length of the square loop and the width of the strip are fabricated on an RF-301 substrate with a thickness of 0.8 mm. The experiment results show that the resonant peak frequency and value of the bistatic RCS for the ELC resonator were 4.305 GHz and -30.39 dBsm, whereas those of the proposed IDC resonator were 3.295 GHz and -36.91 dBsm. Therefore, the size of the resonator is reduced by 23.5% based on the measured resonant peak frequency of the RCS characteristic.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.9
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• pp.928-935
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• 2013

This paper proposed a combining technique of feature vectors which improves the performance of radar target recognition. The proposed method obtains more information than monostatic or bistatic case by combining extracted feature vectors from two receivers. For verifying the performance of the proposed method, we calculated monostatic and bistatic RCS(BRCS) of three full-scale fighters by changing the receiver position. Then, the scattering centers are extracted using 1-D FFT-based CLEAN from the calculated RCS data. Scattering centers are used as feature vectors for neural network classifier. The results show that our method has the better performance than the monostatic or bistatic case.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.11
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• pp.886-893
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• 2017

Recently, for detection of low-RCS targets, bistatic radar and multistatic radar have been widely employed. In this paper, we present the process of deriving the received signal modeling of the bistatic MIMO radar system and deals with the performance analysis of applying the bistatic signal to the ML arrival angle estimation algorithm. In case of the ML algorithm, as the number of the targets increases, azimuth search dimension for DOA estimation also increases, which implies that the ML algorithm for multiple targets is computationally very intensive. To solve this problem a closed-form expression of estimation error is presented for performance analysis of the algorithm.

• IEMEK Journal of Embedded Systems and Applications
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• v.17 no.1
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• pp.67-76
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• 2022

Monostatic/Bistatic inverse synthetic aperture radar (ISAR) images are two-dimensional radar cross section (RCS) distributions of a target. When there are many targets in a single radar beam, ISAR images are generated with targets overlapped, so it is difficult to perform the targets identification using the trained database. In addition, it is inefficient to perform target identification using only single monostatic and bistatic ISAR images separately because each method has its own advantages and weaknesses. Therefore, this paper analyzes multiple targets identification performances using monostatic/bistatic ISAR images and proposes a method of identification through fusion of two ISAR images. To identify multiple targets, we use image combination technique using trained single target images. Simulation results show effectiveness of proposed method.

• Journal of information and communication convergence engineering
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• v.2 no.3
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• pp.153-156
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• 2004

A planar active retrodirective four-element array with subharmonic phase conjugation mixers based on anti-parallel diode pairs (APDPs) is proposed. As compared to previous phase conjugation mixers using twice RF frequency for LO frequency, the proposed conjugation mixers need only half RF frequency so that it can be easily applied for millimeter-wave applications. Receiving, transmitting, local oscillator, and intermediate frequencies are 5.79, 5.81, 2.9 GHz, and 10 MHz. Monostatic RCS and Bistatic RCS measurements at source locations of $0^{\circ},\;-20^{\circ},\;and\;28^{\circ}$ show good agreement with the calculated data.

• The Journal of Korean Institute of Information Technology
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• v.16 no.12
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• pp.93-100
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• 2018

Inverse Synthetic Aperture Radar(ISAR) image is 2-dimensional radar cross section distributions of a target. For target approaching along radar's line of sight(LOS), the bistatic ISAR can compensate for the weakness of the monostatic ISAR which can not obtain the vertical resolution of the image. However, bistatic ISAR have longer processing times and variability in scattering mechanisms than monostatic ISAR, so target identification using only bistatic ISAR images can be inefficient. Therefore, this paper analyzes target identification performance using monostatic and bistatic ISAR images of targets approaching along radar's LOS and proposes a method of target identification through fusion of two radars. Simulation results demonstrate that identification performance through fusion is more efficient than identification performance using only monostatic, bistatic ISAR images.