• 항공우주시스템공학회지
• /
• 제8권2호
• /
• pp.40-48
• /
• 2014

In this paper, a prototype of GPS jammer localization system for precise landing is developed. The jammer localization system consists of the four jamming signal receivers for collecting RF signal, one central tracking station for estimating jammer position, and one monitoring station for displaying estimated position on the map. In order to estimate jammer location TDOA and AOA algorithm are introduced, and the function and design parameters of the developed prototype are proposed. CW, DSSS, Swept CW jamming signals were generated and used. From the results, it can be confirmed that developed system meets the performance goal.

• Journal of Positioning, Navigation, and Timing
• /
• 제10권3호
• /
• pp.179-187
• /
• 2021

To estimate the location of the train, we consider an integrated navigation system that combines Inertial Navigation System (INS) and Global Navigation Satellite System (GNSS). This system provides accurate navigation results in open sky by combining only the advantages of both systems. However, since measurement update cannot be performed in GNSS signal blocked areas such as tunnels, mountain, and urban areas, pure INS is used. The error of navigation information increases in this area. In order to reduce this problem, the train's Non-Holonomic Constraints (NHC) information can be used. Therefore, we deal with the INS/GNSS/NHC integrated navigation system in this paper. However, in the process of installing the navigation system on the train, a Mounting Misalignment Error of the IMU (MMEI) inevitably occurs. In this case, if the NHC is used without correcting the error, the navigation error becomes even larger. To solve this problem, a method of easily estimating the MMEI without an external device is introduced. The navigation filter is designed using the Extended Kalman Filter (EKF) by considering the MMEI. It is assumed that there is no vertical misalignment error, so only the horizontal misalignment error is considered. The performance of the integrated navigation system according to the presence or absence of the MMEI and the estimation performance of the MMEI according to the method of using NHC information are analyzed based on simulation. As a result, it is confirmed that the MMEI is accurately estimated by using the NHC information together with the GNSS information, and the performance and reliability of the integrated navigation system are improved.

• 대한원격탐사학회지
• /
• 제23권5호
• /
• pp.365-373
• /
• 2007

Car navigation system is a key application in geographic information system and telematics. A recent trend of car navigation system is using real video captured by camera equipped on the vehicle, because video has more representation power about real world than conventional map. In this paper, we suggest a visual car navigation system that visually represents route guidance. It can improve drivers' understanding about real world by capturing real-time video and displaying navigation information overlaid directly on the video. The system integrates real-time data acquisition, conventional route finding and guidance, computer vision, and augmented reality display. We also designed visual navigation controller, which controls other modules and dynamically determines visual representation methods of navigation information according to current location and driving circumstances. We briefly show implementation of the system.

• Journal of Astronomy and Space Sciences
• /
• 제24권4호
• /
• pp.389-396
• /
• 2007

The Global Navigation Satellite System (GNSS) becomes more important and is applied to various systems. Recently, the Galileo navigation system is being developed in Europe. Also, other countries like China, Japan and India are developing the global/regional navigation satellite system. As various global/regional navigation satellite systems are used, the navigation ground system gets more important for using the navigation system reasonably and efficiently. According to this trend, the technology of GNSS Ground Station (GGS) is developing in many fields. The one of purposes for this study is to develop the high precision receiver for GNSS sensor station and to provide ground infrastructure for better performance services on navigation system. In this study, we consider the configuration of GNSS Ground Station and analyze function of Monitoring and Control subsystem which is a part of GNSS Ground Station. We propose Monitoring and Control subsystem which contains the navigation software for GNSS Ground System to monitor and control equipments in GNSS Ground Station, to spread the applied field of navigation system, and to provide improved navigation information to user.

• 한국군사과학기술학회지
• /
• 제11권2호
• /
• pp.66-72
• /
• 2008

A distributed missile system is composed of command control center, radar and launcher which exchange information each other to use wire or wireless network. The distributed missile system is required mobility for operational convenience and survivability. Also missile system requests land navigation system to provide relatively accurate attitude. For reason of these requirements, each subsystem needs land navigation which provides information of position and attitude. This paper represents operational concept for land navigation to consider operational environment and concrete operational procedure to apply the operational concept. In state that there is no operation for land navigation of distributed missile system internally so for, this paper could be helped to establish operational concept and procedure of this kind of system.

• 한국항공운항학회지
• /
• 제21권1호
• /
• pp.8-14
• /
• 2013

As GNSS(Global Navigation Satellite System) is used in various filed, many countries establish GNSS system independently. But GNSS system has the limitation of accuracy and stability in stand-alone mode, because this system has error elements which are ionospheric delay, tropospheric delay, orbit ephemeris error, satellite clock error, and etc. For overcome of accuracy limitation, the DGPS(Differential GPS) and RTK(Real-Time Kinematic) systems are proposed. These systems perform relative positioning using the reference and user receivers. ETRI(Electronics and Telecommunications Research Institute) is developing precision navigation system in point of extension of GNSS usage. The precision navigation system is for providing the precision navigation solution to common users. If this technology is developed, GNSS system can be used in the fields which require precision positioning and control. In this paper, we introduce the precision navigation system and perform design and algorithm verification.

• 전기학회논문지
• /
• 제59권11호
• /
• pp.2048-2057
• /
• 2010

Is this paper, a pedestrian inertial navigation system with vision is proposed. The navigation system using inertial sensors has problems that it is difficult to determine the initial position and the position error increases over time. To solve these problems, a vision system in addition to an inertial navigation system is used, where a camera is attached to a pedestrian. Landmarks are installed to known positions so that the position and orientation of a camera can be computed once a camera views the landmark. Using this position information, estimation errors in the inertial navigation system is compensated.

• 한국항해항만학회지
• /
• 제33권7호
• /
• pp.463-467
• /
• 2009

In near future, more congested and dangerous marine traffic environment due to the rapid marine traffics increase and ship handling difficulty by enlargement of ship size is predicted. In this paper, an navigation supporting system proposal made to enhance the safe navigation by providing the collision avoidance informations to the navigator via marine traffic environment assessment. Proposed navigation supporting system displays results of marine traffic environment assessment, degree of the dangers and gives reason of danger which is enhance situational awareness of navigator. For this purpose, results of marine traffic environment assessment which is obtained via real time assessment sent to the designated server and through the connection with navigation supporting system navigator being enable to see all those informations on the computer screen Navigator would utilize those information to make a decision in the difficult waterways and thus safe navigation could be enhanced.

• 제어로봇시스템학회논문지
• /
• 제5권7호
• /
• pp.827-835
• /
• 1999

In this paper, a dead reckoning navigation system for differential drive mobile robots is presented. The navigation system consists of two incremental encoders and a gyroscope. We have built a third order polynomial function for compensating the nonlinear scale factor errors of the gyroscope. We utilize an indirect Kalman filter that feeds back estimated errors to the main navigation system. Also, the observability of the filter is analyzed in order to systematically evaluate the filter's performance. Experimental results show that the proposed navigation system provides a reliable position and heading angle by mutually compensating the encoder and the gyroscope errors. The proposed filter also reduces the computational burden and enhances the navigation system's reliability. The observability analysis confirms the characteristics of inevitably unbounded position error growth in dead reckoning navigation systems.

• 융합보안논문지
• /
• 제8권2호
• /
• pp.87-94
• /
• 2008

본 논문에서는 유도무기체계의 관성항법장치 기술에 대한 사항과 발전추세에 대해 연구하였다. 항법장치는 여러 곳에 일반적으로 많이 사용되고 있다. 그중 관성항법장치는 무기체계에 부착되어 사용됨에 따라 많은 관심들을 가지고 장치의 개발과 발전을 위한 연구가 가속화되고 있다. 따라서 본 논문에서는 유도무기체계 관성항법장치의 개발동향, 기능 및 구성, 종류, 작동기술에 대해 연구하였다.