• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.3
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• pp.756-763
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• 2015

NAVWAR (NAVigation WARfare) such as an integral part of EW (Electronic Warfare) for making navigation systems malfunctioning expands rapidly in the future military warfare. First of all, Navigation systems of ground radio and satellite were investigated. And the definition of NAVWAR and vulnerability related to GNSS were analyzed. As a result, we propose the development direction for future navigation system such as constructing eLoran system, developing an integrated receiver, establishing alert steps of watch system, and so on.

• Journal of Positioning, Navigation, and Timing
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• v.11 no.4
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• pp.229-238
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• 2022

This paper addresses on the International technical trends, standards, and development status of terrestrial radionavigation system to provide more accurate and fail-safe Positioning, Navigation, and Timing (PNT) Information available in maritime navigation environment. We analyze the performance result of pilot service in enhanced Long range navigation (eLoran) testbed environment using Low Frequency (LF) signal, and describe the development status of Ranging-Mode (R-Mode) system using Medium Frequency (MF) and Very High Frequency (VHF) to meet the Harbor Entrances and Approaches (HEA) requirement of International Maritime Organization (IMO) within 10m position accuracy. Furthermore, we present an architecture for integrated service of satellite-terrestrial navigation system and future maritime applicable fields. As the core information infrastructure of future navigation for 4th industrial revolution, this paper will be contributed to determining the direction of present and future to provide fail-safe PNT service with Global Navigation Satellite System (GNSS) based on the technical enhancement of terrestrial integrated navigation system.

• Journal of Advanced Navigation Technology
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• v.27 no.1
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• pp.50-56
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• 2023

INS(Inertial Navigation System) calculates navigation information using a vehicle's acceleration and angular velocity without the outside information. However, when navigation is performed for a long time, navigation error gradually diverges and the performance decreases. To enhance INS's performance, the rotation of inertial measurement unit is developed to compensate error sources of inertial sensors, which is called RINS(Rotational Inertial Navigation System). This paper analyzes the influence of several errors for dual-axis RINS and the shows the results using simulation.

• Journal of Navigation and Port Research
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• v.42 no.2
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• pp.79-86
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• 2018

Common Maritime Data Structure (CMDS) is commonly used by shore and ship users in e-Navigation data domain. In the overarching of e-Navigation architecture, IHO uses S-1XX, a digital exchange standard for next-generation marine information, as data exchange standard. The current CMDS has the advantage of intuitively recognizing the overall structure of e-Navigation. However, it has disadvantage in that it does not allow stakeholders to easily understand benefits that e-Navigation can provide when implementing e-Navigation. In this study, the direction of improving existing system for effective e-Navigation implementation was proposed considering RCOs (Risk Control Options) with expected composition of ship/ shore/ communication system by sector.

• Journal of Biosystems Engineering
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• v.34 no.4
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• pp.278-285
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• 2009

Navigation system is applied in variety of fields including the simple location positioning, autopilot navigation of unmanned robot tractor, autonomous guidance systems for agricultural vehicles, construction of large field works that require high precision and map making process. Particularly utilization of GPS (Global Positioning System) is very common in the present navigation system. This study introduces a navigation system for autonomous field robot that travels to the pre-input path using GPS information. Performance of the GPS- based navigation is highly depended on its receiving rate because GPS receivers do not acquire any navigation information in the period between the refresh intervals. So this study presents an algorithm that improves an accuracy of the navigation by estimation the positional information during the blind period of a low rate GPS receiver. In fact the algorithm calculated the robot's heading in a 50 Hz rate, so the blind period of an 1 Hz GPS receiver is extensively covered. Consequently implementation of the algorithm to the GPS based navigation showed an improvement in guidance accuracy. The conventional field robot directly carried an expensive control computer and sensors onboard, therefore the miniaturization and weight reduction of the robot was limited. In this paper, the field robot carried only communication equipments such as GPS module, normal RC receiver, and bluetooth modem. This enabled the field robot to be built in an economic cost and miniature size.

• Archives of design research
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• v.20 no.3 s.71
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• pp.203-214
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• 2007

This study proposes an information retrieval method reflecting the user's preferences based on the fuzzy set theory to develop information contents which support pedestrian's navigation. Firstly, the research evaluated subjects' preferences on commercial spaces set to a hypothetical destination. Also it surveyed the causal relationship between the visual characteristics and the emotional characteristics to propose methods of Navigation Knowledge Base (NKB). The NKB was composed of three elements; 1. the correlation model between emotional characteristics, 2. the causal relationship between visual characteristics and emotional characteristics, 3. the transformation model between visual characteristics and the physical characteristics. Secondly, this study classified the pedestrian's destination search into 4 types with his or her preferences and the time conditions limited during navigation. For each type it presented the Destination Search Algorithm (DSA). Finally, the research simulated the destination search in 4 navigation types using NKB and DSA and verified the availability of the information retrieval method reflecting pedestrian's preferences. In conclusion, the proposed information search method will be applied to reflect the user's preferences to develop information appliances.

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.530-531
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• 2008

Recently, navigation system is widely accepted for many car users for its versatile facilities. In Korea, many navigation system include DMB (digial multimedia broadcasting) which is mobile TV broadcasting system standard in Korea. However, there is little works on the navigation systems for the European market where the DVB-T can be used for the multimedia broadcasting. Thus, in this work the navigation system with DVB-T is developed and tested for European market resulting increased profits for the navigation manufacturers.

• Electronics and Telecommunications Trends
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• v.38 no.2
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• pp.12-25
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• 2023

Positioning, navigation, and timing information has become a key element in the national core infrastructure and for emerging technologies, such as autonomous driving, lunar exploration, financial systems, and drones. Therefore, the provision of that information by navigation satellite systems is becoming increasingly important. Existing systems such as GPS (Global Positioning System), GLONASS (GLObal NAvigation Satellite System), and BDS (BeiDou Navigation Satellite System) also provide augmentation, safety-of-life, search & rescue and short message communication and authentication services to increase their competitiveness. Those services and the signals generated for their provision have their own purpose and requirements. This article presents an overview of existing or planned satellite navigation satellite system services and signals, aiming to help understand their current status.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.12
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• pp.2520-2527
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• 2015

Position information is important to carry out military operations. In general, GPS is used to estimate position. However, GPS is vulnerable to jamming due to the low received signal strength, therefore GPS can be easily jammed. The relative navigation is an auxiliary navigation system defined in JTIDS. When GPS is jammed, the relative navigation requires ground reference units on the ground to operate accurately. If the ground reference unit does not exist, nodes operated by the relative navigation depend on the inertial navigation system to identify their position. However, this positioning scheme based on only INS causes accumulative position error, therefore the nodes cannot identify their position accurately for a long time. In this paper, we propose an alternative to reduce position error generated by depending inertial navigation system. In order to verify that the performance of proposed scheme is better than that of the existing scheme, various simulations are conducted.

• Journal of Navigation and Port Research
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• v.46 no.3
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• pp.158-167
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• 2022

The International Maritime Organization's e-Navigation strategy introduces new technologies to ships to support easier and safer navigation. To implement the e-Navigation strategy, it was necessary to develop a common data model, that could meet various requirements across all aspects of the maritime information service. The International Hydrographic Organization's S-100 Universal Hydrographic Data Model was selected, as the basis for the standardization of maritime data products. Three S-100 based product specifications for weather information, collectively called "S-41X", are currently under development by the NOAA's Ocean Prediction Center, for use in the Electronic Chart Display and Information System (ECDIS). This paper describes a design of a grid based S-413 data model out of three S-41X product specifications. Other S-100 data products, which support the gridded data format, were considered. To verify the data model, an encoding test was conducted, using the Korean Meteorological Adminstration's numerical prediction model results.