• Journal of Navigation and Port Research
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• v.44 no.2
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• pp.110-118
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• 2020

With the expansion of the shipping and port logistics industry in the 21st century, the traffic density is continuously increased because of the increase in volumes of world sea freight and fleets, as well as the increase in the causes of potential marine accidents, such as ship collisions and stranding. Accordingly, the International Maritime Organization (IMO) has requested that the installation and operation of VTS should be applied in areas with high risk of marine traffic, and the request should be included as one of the Safety of Life at Sea (SOLAS) regulations. In this paper, the fundamental requirements of the radar system for vessel traffic services were analyzed and the analyzing factors were based on the IALA guideline.s This paper also includes results for the requirement and recommendation analysis on detection distance, target separation, and the target position accuracy of X-band radar. Also, to check if it satisfies the requirement of detection distance, range and azimuth separation of small point targets, and target position accuracy from the IALA guidelines, the test was conducted through the radar image acquired at the VTS center, and hence, the validity of the technical performance requirements was confirmed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.4
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• pp.217-228
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• 2020

The ROK Army must detect the enemy's location and the type of artillery weapon to respond effectively at wartime. This paper proposes a radar positioning model by applying a scenario-based robust optimization method i.e., binary integer programming. The model consists of the different types of radar, its available quantity and specification. Input data is a combination of target, weapon types and enemy position in enemy's attack scenarios. In this scenario, as the components increase by one unit, the total number increases exponentially, making it difficult to use all scenarios. Therefore, we use partial scenarios to see if they produce results similar to those of the total scenario, and then apply them to case studies. The goal of this model is to deploy an artillery locating radar that maximizes the detection probability at a given candidate site, based on the probability of all possible attack scenarios at an expected enemy artillery position. The results of various experiments including real case study show the appropriateness and practicality of our proposed model. In addition, the validity of the model is reviewed by comparing the case study results with the detection rate of the currently available radar deployment positions of Corps. We are looking forward to enhance Korea Artillery force combat capability through our research.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.4
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• pp.337-346
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• 2003

This paper describes on the system and method for automatically tracking and real-time monitoring the position of target ships relative to the own ship using a PC based radar system that displays radar images and electronic charts together on a single PC screen. This system includes a simulator for generating the GGA and VTG information of target ships and a simulator for generating the TTM and OSD outputs from a ARPA radar and then host computer accepts NMEA0183 sentences on the maneuvering information of target ships from these simulators. The results obtained are summarized as follows；1. The system developed this study can be used as a range finder for measuring the distance between two ships and as a device for providing the maneuvering information such as distance and bearing to target ships from own ship on ECS screen. 2. From the result of position tracking for a selected target ship tracked with an update rate of 5 seconds using the $\alpha$-$\beta$ tracker, we concluded that the smoothing effect by the $\alpha$-$\beta$tracker was very effective and stable except in the time interval until about one minute after the target is detected. 3. From the fact that the real-time maneuvering information of tracked ship targets via a local area network (LAN) from a host computer installed a radar target extractor was successfully transferred to various monitoring computers of ship, we concluded that this system can be used as a sub-monitoring system of ARPA radar.

• Journal of Navigation and Port Research
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• v.30 no.7
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• pp.611-615
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• 2006

This paper proposes a method for generating radar images used in a ship handling simulator, which includes mathematical logics based on radar equations and information from Openflight format files. In order to make radar image much similar to that of real radar in PPI type, the proposed mathematical logic derives radar video signals under the consideration of not only the data form flight format file of simulation scenes, but also geographical radar's position. The proposed method is considered useful to make radar images in ship handling simulator with accuracy and reality.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.61-66
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• 2006

This paper proposes a method for generating radar images used in ship handling simulator, which includes mathematical logics based on radar equations and information from Openflight format files. In order to make radar image much similar to that of real radar in PPI type, the proposed mathematical logic derives radar video signals under the consideration of riot only the data form flight format file of simulation scenes, but also geographical radar's position. The proposed method is considered useful to make radar images in ship handling simulator with accuracy and reality.

• Journal of Korea Water Resources Association
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• v.41 no.11
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• pp.1153-1162
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• 2008

The use of radar rainfall for hydrological appraisal has been a challenge due to the limitations in raw data generation followed by the complex analysis needed to come up with precise data interpretation. In this study, RAIDOM (RAdar Image DigitalizatiOn Method) has been developed to convert synthetic radar CAPPI(Constant Altitude Plan Position Indicator) image data from Korea Meteorological Administration into digital format in order to come up with a more practical and useful radar image data. RAIDOM was used to examine a severe local rainstorm that occurred in July 2006 as well as two other separate events that caused heavy floods on both upper and mid parts of the HanRiver basin. A distributed model was developed based on the available radar rainfall data. The Flood Hydrograph simulation has been found consistent with actual values. The results show the potentials of RAIDOM and the distributed model as tools for flood prediction. Furthermore, these findings are expected to extend the usefulness of radar rainfall data in hydrological appraisal.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.6
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• pp.822-834
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• 2017

In M&S, radar model is a software module to identify position data of simulation objects. In this paper, we propose a radar performance model for simulations of air defenses. The previous radar simulations are complicated and difficult to model and implement since radar systems in real world themselves require a lot of considerations and computation time. Moreover, the previous radar simulations completely depended on radar equations in academic fields; therefore, there are differences between data from radar equations and data from real world in mission level analyses. In order to solve these problems, we firstly define functionality of radar systems for air defense. Then, we design and implement the radar performance model that is a simple model and deals with being independent from the radar equations in engineering levels of M&S. With our radar performance model, we focus on analyses of missions in our missile model and being operated in measured data in real world in order to make sure of reliability of our mission analysis as much as it is possible. In this paper, we have conducted case studies, and we identified the practicality of our radar performance model.

• Korean Journal of Remote Sensing
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• v.36 no.3
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• pp.441-448
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• 2020

GMTI (Ground Moving Target Indication) radar system can detect ground moving targets and can provide position and velocity information of each target. However, the azimuth position of target has some offset because of the hardware errors such as mechanical tolerances. In this case, an error occurs no matter how accurate the monopulse ratio is. In this paper, target position correction method in azimuth direction has been proposed. The received sum and difference signals of monopulse GMTI system are post-processed to correct the target azimuth angle error. This method is simple and adaptive for nonhomogeneous area because it can be implemented by using only software without any hardware modification or addition.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.1
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• pp.118-128
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• 2017

In this study, we propose a real time inertial navigation system/global positioning system (INS/GPS) integrated smoothing algorithm based on an extended Kalman filter (EKF) and a position damping loop (PDL) for synthetic aperture radar (SAR). Integrated navigation algorithms usually induce discontinuities due to error correction update by the Kalman filter, which are as detrimental to the performance of SAR as the relative position error. The proposed smoothing algorithm suppresses these discontinuities and also reduces the relative position error in real time. An EKF estimates the navigation errors and sensor biases, and all the errors except for the position error are corrected directly and instantly. A PDL activated during SAR operation period imposes damping effects on the position error estimates, where the estimated position error is corrected smoothly and gradually, which contributes to the real time smoothing and small relative position errors. The residual errors are re-estimated by the EKF to maintain the estimation performance and the stability of the overall loop. The performance improvements were confirmed by Monte Carlo simulations. The simulation results showed that the discontinuities were reduced by 99.8% and the relative position error by 48% compared with a conventional EKF without a smoothing loop, thereby satisfying the basic performance requirements for SAR operation. The proposed algorithm may be applicable to low cost SAR systems which use a conventional INS/GPS without changing their hardware configurations.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.10a
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• pp.27-29
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• 2015

Based on IALA guidelines, the fundamental requirements of radar system for vessel traffic services are analyzed in this paper. target separation, target position accuracy, target track accuracy of X-band radar and recommended test conditions are analyzed. Also, in order to check if it satisfies the requirement of target position accuracy from IALA guideline, the test is carried out through processing of radar raw image acquired at VTS center.