• Journal of Korean Society of Coastal and Ocean Engineers
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• v.16 no.1
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• pp.39-46
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• 2004

In the GIS construction to land and sea in Korea, GIS construction on land was completed mostly for big cities by NGIS(National Geography Information System) business. However, Marine GIS being constructed by the National Oceanographic Research Institute is still constructing geography information and definition of attribute information and real condition. We have done researches to get maximized ripple effect linking GPS and Navigation techniques on GIS. GPS in accuracy is divided into navigation and precise surveying equipments. Now, GPS technology has been developed very much and with low price GPS equipments are being introduced. But costs on the GPS equipments are high yet. Therefore, the GPS equipments for navigation can be substituted by cheap GPS equipments in a car or ship. In this paper, the authors developed algorithm to convert ellipsoid coordinate between WGS84 and Bessel ellipsoid and to analyze map projection between BESSEL ellipsoid and UTM plane coordinate system. And the author developed ship navigation system with cheap GPS equipments using algorithm of ellipsoid conversion and map projection. The authors proposed the necessity on constructing Internet GIS to manage many ships.

• Journal of Advanced Navigation Technology
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• v.22 no.6
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• pp.566-576
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• 2018

The C-ITS requires the lane level positioning of the vehicle in the land transportation environment, and it is most effective to utilize the GNSS. In the precision positioning system based on satellite navigation, the evaluation of dynamic environment of lane level positioning performance should be accompanied and the evaluation system configuration should be preceded. In this paper, we selected performance indicators, assessment equipment, and reliability of reference equipment for evaluation of precision positioning user systems based on the GNSS. The performance evaluation system described above is applied to a real system, and the performance evaluation tool developed for the evaluation system is described. The numerical performance evaluation was carried out based on the data collected by carrying out the actual testbed driving. The performance evaluation by the actual driving trajectory and driving image comparison was performed to derive and analyse the evaluation results of the vehicle lane level positioning user system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.14-19
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• 2020

This paper proposes a precise drone-positioning technique using a differential global positioning system (DGPS). The proposed system consists of a reference station for error correction data production, and a mobile station (a drone), which is the target for real-time positioning. The precise coordinates of the reference station were acquired by post-processing of received satellite data together with the reference station location data provided by government infrastructure. For the system's implementation, low-cost commercial GPS receivers were used. Furthermore, a Zigbee transmitter/receiver pair was used to wirelessly send control signals and error correction data, making the whole system affordable for personal use. To validate the system, a drone-tracking experiment was conducted. The results show that the average real-time position error is less than 0.8 m.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.8
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• pp.1619-1625
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• 2017

Civil global navigation satellite system (GNSS) does not meet user performance requirements for specific PNT (Positioning, Navigation, and Time) applications. Therefore, various differential systems are used to augment GNSS for improving positioning accuracy and integrity. The MTSAT satellite augmentation system (MSAS) is the Japanese satellite based augmentation system. This paper is for analyzing the characteristics of Japanese MSAS in Korean peninsula. First of all, it was done for analyzing not only DGNSS navigation signal but also the navigation parameter through simulation and experimental tests. As a result of data analyses, the sufficient navigation satellites to determine 3-D position based on DGNSS are simultaneously available at MSAS monitering station and the southern region of Korean peninsula. It was verified that the carrier to noise signals are stable to maintain the reliable 3-D position and that the level of 2m (2drms) accuracy is very similar to the ordinary worldwide DGNSS as well.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.447-450
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• 2006

최근 국내외에서 재래식 폭탄의 정확도와 사거리를 향상시킨 정밀 유도 무기에 관한 연구가 활발하게 진행 중에 있다. 국내에서는 국방과학연구소의 주도로 재래식 폭탄에 GAK(GPS Adapter Kit)를 장착하는 연구가 진행 중이다. GAK는 GPS/INS 복합 항법 모듈을 내장한 사거리 연장 유도 키트의 일종으로 폭탄이 투하되면 접혀 있던 날개가 전개되고 이후 날개의 플래퍼론을 구동하여 유도 조종을 수행한다. 복합 항법 모듈은 상용의 MEMS IMU, 내장형 GPS 수신기 및 항법 컴퓨터와 실시간 운영 체제에서 구동되는 항법 소프트웨어로 구성된다. 본 논문에서는 복합 항법 모듈의 비행 시험 결과를 제시하였다. 시험 결과 항법 모듈이 실시간으로 정상적인 동작을 수행하였으며 GPS 유도 폭탄의 유도 조종에 적합한 항법 정보를 제공하였음을 확인하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.11a
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• pp.195-197
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• 2022

위성항법시스템(GPS)은 편리성, 활용도 등으로 인해 항법, 이동통신, 금융, 전력 등 여러 분야(측위·항법·시각)에서 사용하고 있다. 위성이 지구로부터 약 2만키로미터 떨어져 있어 위성신호 수신 세기가 약해 외부로부터 전파간섭이나 교란 등 보안에 취약한 단점이 있다. 주요국(미국, 유럽, 중국, 인도 등)은 보안을 강화하여 독자적인 위성항법 시스템을 구축하여 운영하고 있다. 우리나라도 지상기반(eLoran)과, 위성기반(KPS)의 항법시스템을 구축중이다. 시스템 구축이 완료되면 한층 강화된 국가 PNT 체계 구축으로 만일의 사태에 발생할 수 있는 상황에 대비할 수 있을 것으로 기대하고 있다. 본 연구에서는 지상기반, 위성기반의 항법시스템에 대한 핵심 기능과 추진계획을 기술하였으며, 관련 연구개발을 통해 더욱 정밀한 서비스 제공으로 해양뿐만 아니라 자율주행 이동체, 무인기 등 여러 산업 분야에 서비스를 확대해 나갈 계획이다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.163-166
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• 2006

본 논문에서는 지상송신국 기반의 로란-C 전파항법시스템이 위성항법시스템(GNSS)의 등장이후 급속한 이용자 감소로 운영의 효율성이 떨어짐에 따라 다양한 각도의 로란-C 성능평가를 실시하여 활용능률 향상방안을 제안하였으며, 국가항법시스템의체계인 관리를 위해 DGPS시스템과 로란-C를 연계한 GNSS 정보센터를 운영하여 GPS는 물론 Galileo, GLONASS 등 위성항법시템 전반의 상황을 모니터링하고 GNSS 불능 시 로란-C를 BACK-UP시스템으로 활용한다면 GNSS 장애로 인한 국가적대혼란의 예방함께 체계적인 전파항법시스템 관리가 가능할 것으로 결론하였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.12
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• pp.1086-1092
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• 2012

It has been studied for DGPS/INS(Differential Global Positioning System/Inertial Navigation System) to offer the more precise and reliable navigation data with the aviation industry development. The flight performance evaluation of navigation system is very significant because the reliability of navigation data directly affect the safety of aircraft. Especially, the high-level navigation system, as DGPS/INS, need more precise flight performance evaluation method. The performance analysis is performed by comparing between the DGPS/INS navigation data and reference trajectory which is more precise than DGPS/INS. The GPS receiver, which is capable of post-processed CDGPS(Carrier-phase DGPS) method, can be used as reference system. Generally, the DGPS/INS is estimated the CG(Center of Gravity) point of aircraft while the reference system is output the position of GPS antenna which is mounted on the outside of aircraft. For this reason, estimated error between DGPS/INS and reference system will include the error due to lever arm. In order to more precise performance evaluation, it is needed to compensate the lever arm. This paper presents procedure and result of flight test which includes lever arm compensation in order to verify reliability and performance of DGPS/INS more precisely.

• Journal of Navigation and Port Research
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• v.42 no.1
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• pp.17-24
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• 2018

The Russian Global Navigation Satellite System (GLONASS) has been fully recovered since October 2011, and it has been significantly modernized. The recently launched GLONASS 752 was set for successful performance on October 16, 2017 and has resulted in 24-satellite constellation with 22 second-generation (GLONASS-M) satellites, and a third-generation (GLONASS-K) satellite. Therefore, this paper is focused on not only the identified navigation parameters, but also the performance analysis of the project based on its real data received from the studied satellites. It is verified that the 5-11 satellites are available for receiving navigation signal at this time. The obtained values of GDOP, PDOP, HDOP, VDOP, and TDOP are 2.790, 2.424, 1.169, 2.123, and 1.381, noted respectively in standard deviation. In fact, the level of positioning precision is about 1.4m in standard deviation. As a result, the positioning performances of the measured GLONASS and GPS are virtually identical. Therefore, we determine that the GLONASS is expected to be expanded for future applications.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.2
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• pp.139-144
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• 2016

This paper provides an overview of recent trends in sensor fusion technologies for vehicle positioning. The GNSS by itself cannot satisfy precision and reliability required by autonomous driving. We survey sensor fusion techniques that combine the outputs from the GNSS and the inertial navigation sensors such as an odometer and a gyroscope. Moreover, we overview landmark-based positioning that matches landmarks detected by a lidar or a stereo vision to high-precision digital maps.