• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.11
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• pp.3121-3129
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• 2009

Conventional marine radar systems utilize pulse radar which is capable of high-power transmissions and is effective for remote detection purposes. A pulse radar is most commonly used on medium or large vessels due to its expensive installation and maintenance costs. I propose the use of a Frequency Modulated Continuous Wave (FMCW) radar system operated at low-power and high-resolution instead of the conventional pulse-radar based system. The transmitted and received signals of the FMCW radar system were theoretically analyzed and radar signal processing design and simulation experiments were performed to detect the range and speed. Intermediate Frequency (IF) signal mixed with virtual transmit and receive signals were generated to perform FMCW radar signal processing simulations where the IF signal underwent noise reduction through a lowpass filter. The maximum frequency was derived through the sample interval of the FFT size instead of using A/D converter. This maximum frequency was used to get the frequency range and frequency speed which were in turn used to calculate the range and speed. The virtual beat frequency generated using MATLAB is utilized to analyze the beat frequency used in the actual FMCW radar system signal processing. The differences in the range and speed of the beat frequency signals are processed and analyzed.

• Journal of Convergence for Information Technology
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• v.10 no.12
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• pp.31-38
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• 2020

Radar signal identification of electronic warfare is a technology that recognizes the pulse repetition interval (PRI) from a set of pulse description words (PDWs) generated by the signal receiver. Conventionally batch processing is widely used in which a number of PDWs are collected as a unit and identifies PRI from the batch. In this paper, we propose a feature extraction algorithm based on the streaming process. This technique does not wait to form a batch. Whenever a PDW(Pulse Description Word) is generated from the signal receiver, the streaming process tries to form a cluster of PDWs, and makes the DTOA (Difference of Time of Arrival) histogram, finds out the frame PRI based on the concentration ratio, and decides the number of stagger stages. Experiments proved that the proposed algorithm derives stable recognition results as the cluster size increases.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.8
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• pp.97-103
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• 2014

Signal processing technique of linear frequency modulation-frequency shift keying (LFM-FSK) waveform has been introduced for rear view radars of an automobile. LFM-FSK waveform consists of two sequential stepped frequency waveforms with some frequency offset, and thus, can be used to generate inverse synthetic aperture radar (ISAR) images of rear view target of an automobile. However, ISAR images can often be blurred due to inter-pulse phase errors. To resolve this problem, one-dimensional (1-D) entropies of high resolution range profiles (HRRP) are minimized with the help of particle swarm optimization (PSO). The searching space used in PSO is adaptively adjusted by the use of information on the target's velocity obtained from LFM-FSK waveforms. Simulation results show that the proposed method can generate well-focused ISAR images.

• Journal of the Korea Convergence Society
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• v.13 no.1
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• pp.43-50
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• 2022

In this paper, it is shown how the performance of the monopulse algorithm in additive noise is evaluated. In the previous study, the performance analysis of the amplitude-comparison monopulse algorithm was conducted via the first-order and second-order Taylor expansion of four variables. By defining two new random variables from the four variables, it is shown that computational complexity associated with two random variables is much smaller than that associated with four random variables. Performance in terms of mean square error is analyzed from Monte-Carlo simulation. The scheme proposed in this paper is more efficient than that suggested in the previous study in terms of computational complexity. The expressions derived in this study can be utilized in getting analytic expressions of the mean square errors.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.11
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• pp.1171-1177
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• 2009

A missile warning radar is an essential sensor for active protection system to detect antitank missile in all weather environments. This paper introduces missile warning radar for main battle tank and presents the results of the design and implementation of the radar signal processor using high speed multi-DSP. The key algorithms include adaptive CF AR, weighted linear fitting algorithm, S/W tracking capability, and threat decision and present test result.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.7
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• pp.730-736
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• 2013

Time-domain clutter generation model for airborne pulse doppler phase-array radar is presented. Time-domain surface clutter signal is generated assuming earth of a sphere and considering geometry of a clutter patch, and generation of sub-array clutter signal is presented. The generated sub-array clutter signal can be used by simulation input signal in various radar applications of DBF(Digital Beamforming), ABF(Adaptive Beamforming), Stap(Space-Time Adaptive Processing) and etc.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.8
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• pp.911-918
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• 2010

With limitation of frequency bandwidth, the range accuracy of typical radars is limited. In this paper, for short distance measurements, the use of an AM(Amplitude Modulated) radar which provides improved range accuracy is proposed. The AM radar signal consists of a carrier frequency signal and double-sideband components. The fabricated AM radar operates with +10 dBm output power and 35 dB receiver gain at 24.128 GHz center frequency with 20 MHz bandwidth, and the range accuracy is measured as ${\pm}15\;cm$.

• Atmosphere
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• v.29 no.2
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• pp.197-211
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• 2019

The observational sensitivity of dual-polarization weather radar was quantitatively analyzed by using two different pulse widths. For this purpose, test radar scan strategy which consisted of consecutive radar scan using long (LP: $2{\mu}s$) and short (SP: $1{\mu}s$) pulses at the same elevation angle was employed. The test scan strategy was conducted at three operational S-band dual-polarization radars (KSN, JNI, and GSN) of Korea Meteorological Administration (KMA). First, the minimum detectable reflectivity (MDR) was analyzed as a function of range using large data set of reflectivity ($Z_H$) obtained from JNI and GSN radars. The MDR of LP was as much as 7~22 dB smaller than that of SP. The LP could measure $Z_H$ greater than 0 dBZ within the maximum observational range of 240 km. Secondly, polarimetric observations and the spatial extent of radar echo between two pulses were compared. The cross-polar correlation coefficient (${\rho}_{hv}$) from LP was greater than that from SP at weak reflectivity (0~20 dBZ). The ratio of $Z_H$ (> 0 dBZ) and ${\rho}_{hv}$(> 0.95) bin to total bin calculated from LP were greater than those from SP (maximum 7.1% and 13.2%). Thirdly, the frequency of $Z_H$ (FOR) during three precipitation events was analyzed. The FOR of LP was greater than that of SP, and the difference in FOR between them increased with increasing range. We conclude that the use of LP can enhance the sensitivity of polarimetric observations and is more suitable for detecting weak echoes.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.9
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• pp.947-954
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• 2010

The decision of threat target in the MWR(Missile Warning Radar) of GVES(Ground Vehicle Equipment System) such as MBT(Main Battle Tank) is very important. Threat decision is judged by angular rate and the accurate azimuth calculation for good threat decision is very important. The angular rate is dependent upon the direction of an approaching target. The target is classified into a threat or non-threat using a boundary condition of the angular rate. This paper presents the eighth azimuth calculation methods and compares the results.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.1
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• pp.94-102
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• 2018

In this paper, the wideband mono-pulse radar using AGC and limiter is designed. The output response characteristics of the mono-pulse radar using AGC and limiter are analyzed, respectively. In addition, the output response for jamming input signals is analyzed. The range tracking loop in the mono-pulse radar has robust output response to the noise jamming input signal. Although the output settling response of the AGC-based mono-pulse radar is larger than that of the limiter-based mono-pulse radar, the AGC-based mono-pulse radar has robustness to the noise jamming input signal due to feedback loop.