• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.1121-1124
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• 2009

면적강우량은 수치예보모형(NWP; Numerical Weather Prediction)이나 분포형 강우유출모형 등에서 가장 중요한 입력변수이다. 기상레이더는 광범위한 시공간분해능을 지닌 강우관측기기로서 널리 이용되고 있다. 레이더 반사도 자료를 이용한 강우추정에 대한 연구는 Z-R 관계식을 이용한 방법, 지상우량계와 연계한 통계적인 방법 등 다양하게 전개되어 왔다. 일반적으로 많이 사용되는 Marshall and Palmer(1948)가 제시한 Z-R 관계식은 층운형 강우에는 비교적 타당한 결과를 얻을 수 있지만 적운형 강우에 대해서는 그러하지 못하다. 또한 지상우량계와 연계한 방법은 주로 geostatistic 기법(ordinary kriging, co-kringing, kriging with external drift 등)을 사용하지만, 배리오그램(variogram)을 작성해야 되는 등 계산절차가 복잡하고 시간이 많이 걸려 실무에 적용하여 실시간으로 강우정보를 제공하기에는 다소 무리가 따른다. 따라서 본 연구에서는 지상우량계로 관측된 강우량과 레이더 추정강우 사이의 보정계수를 이용한 실시간 Z-R 관계식으로 레이더강우를 추정할 경우 발생될 수 있는 문제점들을 제시하고 개선방안을 모색하여 보다 정확한 레이더 강우를 추정하고자 하였다. 연구 대상지역은 부산레이더 반경 240km 이내 지역이며, 강우사상으로는 2002년 8월 31일 (태풍 "루사")의 레이더 반사도 자료를 이용하였다. 또한, 지상관측 강우량자료는 AWS(Auto Weathering System) 중에서 부산레이더 관측범위 내에 존재하는 68곳의 1시간 누적강우량을 사용하였다. 연구 결과, 기존의 실시간 Z-R 관계식을 이용할 경우 단순히 지상우량계와 레이더 강우 사이의 보정계수를 사용하면서 물리적인 범위를 벗어나 과대 추정되는 결과를 발생시켰다. 본 연구에서는 이렇게 과대 추정되는 부분을 제한함으로써 보다 현실적이고 타당한 면적강우량을 산정할 수 있었다.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.39 no.2
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• pp.116-122
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• 2002

A timing signal board which can be used to analyze EA effect for coherent radar systems is introduced. It is capable of generating the timing signals that are needed for EA test about radar systems in real time. Its function to generate baseband target signal makes it easy to analyze EA effect. Because all parameters of timing signals can be changed by software, it is very easy to configure many kinds of test scenarios.

• Journal of Satellite, Information and Communications
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• v.8 no.4
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• pp.159-163
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• 2013

In this paper, we propose a new method to deinterleave multi-stage stagger PRI signals of pulse radars using the electronic intelligence systems. While former algorithms were based on hardware PRI tracker only using the first deviation of the TOA of radar signals, this paper uses the first and the second deviation of TOA of radar signals and uses the PRI histogram method to deinterleave multiple PRIs of pulse radars. This algorithm can be used for deinterleaving various PRI signals at electronic intelligence systems.

• Journal of the Society of Disaster Information
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• v.16 no.1
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• pp.60-69
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• 2020

Purpose: Cavity growth process monitoring is to periodically monitor changes in common size and topography for general and observational grades to predict the rate of common growth. The purpose of this study is to establish a systematic cavity management plan by evaluating the general and observational class community in a non-destructive method. Method: Using GPR exploration equipment, the acquired surface image and the surrounding status image are analyzed in the GPR probe radargram in depth, profile, and cross section of the location. The exact location is selected using the distance and surrounding markings shown on the road surface of the initial detection cavity, and the test cavity is analyzed by calling the radar at the corresponding location. Result: As a result of monitoring tests conducted at a cavity 30 sites of general and observation grade, nine sites have been recovered. Changes in scale were seen in 21 cavity locations, and changes in size and grade occurred in 13 locations. Conclusion: The under road cavity is caused by various causes such as damage to the burial site, poor construction, soil leakage caused by groundwater leakage, waste and ground vibration. Among them, indirect factors could infer the effects of groundwater and localized rainfall.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.5
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• pp.460-470
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• 2009

In this paper, we described the implementation of the X-Band continuous-wave doppler radar for muzzle velocity measurement. The radar is consisted of microwave transceiver, signal processor, power board, and the measuring program was developed for the operating and field test. The operating frequency of doppler radar is able to set ${\pm}3\;MHz$ with 5 channel from the center frequency, and the output power is 25 dBm. The minimum receiving power is -117 dBm. The radar would obtain the doppler frequency from the artillery, and calculate accurate velocity point and then estimate muzzle velocity. The performance test for this radar was done with 155 mm at barrel and tripod mounted, and also compared the performance with the reference radar. As a result, the performance of the our new radar is equal with the reference one.

• Journal of the Korean earth science society
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• v.35 no.2
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• pp.115-130
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• 2014

The growing possibility of the disaster due to severe weather calls for disaster prevention and water management measures in South Korea. In order to prevent a localized heavy rain from occurring, the rainfall must be observed and predicted quantitatively. In this study, we developed an adjustment algorithm to estimate the radar precipitation applying to the local gauge correction (LGC) method which uses geostatistical effective radius of errors of the radar precipitation. The effective radius was determined from the errors of radar rainfall using geostatistical method, and we adjusted radar precipitation for four heavy rainfall events based on the LGC method. Errors were decreased by about 40% and 60% in adjusted hourly rainfall accumulation and adjusted total rainfall accumulation for four heavy rainfall events, respectively. To estimate radar precipitation for localized heavy rain events in summer, therefore, we believe that it was appropriate for this study to use an adjustment algorithm, developed herein.

• 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.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.831-833
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• 2009

본 논문에서는 추적레이더의 추적 상태를 모의하는 시뮬레이터 개발에 관한 것이다. 먼저 저고도 추적 레이더의 연구내용을 분석 하였고 이를 바탕으로 Matlab을 이용한 추적오차 계산용 수치해석 프로그램을 개발하였다. 본 연구에서는 고도 오차를 계산 할 때 안테나 빔 폭과 지면의 반사계수를 고려하여 좀 더 정밀한 시뮬레이터를 제시 하였다. 제시된 시뮬레이션 결과들이 이론적인 예측 결과와 잘 일치함을 볼 수 있다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.11a
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• pp.178-180
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• 2022

선박충돌사고를 재현하고 분석하기 위해서는 레이더 기반 선박충돌사고 데이터에서 물표 정보를 정확하게 확보하는 것이 매우 중요한 역할을 한다. 이 연구에서는 HSV 색공간과 OpenCV 라이브러리를 이용하여 물표 정보를 추출하는 방법을 분석하였고, 실제 상황에 적용한 프로그램도 개발하였다.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.7
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• pp.85-91
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• 2016

Typically, radar systems change the pulse repetition interval of their modulated signal in order to avoid detection. On the other hand the radar-signal detection system tries to detect the modulation pattern. The histogram or auto-correlation methods are usually used to detect the PRI pattern of the radar signal. However these methods tend to lost the sequence information of the PRI pulses. This paper proposes a PRI-sequence detection algorithm based on the finite-state machine that could detect not only the PRI pattern but also their sequence.