• Journal of Positioning, Navigation, and Timing
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• v.5 no.2
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• pp.59-66
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• 2016

The International GNSS Service (IGS) provides the IGS-Real Time Service (IGS-RTS) corrections that can be used in stand-alone positioning in real time. In this study, the positioning accuracy before and after the application of the corrections to broadcast ephemeris by applying the IGS-RTS corrections at code pseudo-range based stand-alone positioning was compared with positioning result using precise ephemeris. The analysis result on IGS-RTS corrections showed that orbit error and clock error were 0.05 m and 0.5 ns compared to precise ephemeris and accuracy improved by about 8.5% compared to the broadcast ephemeris-applied result when the IGS-RTS was applied to positioning. Furthermore, regionally dispersed five observatories were selected to analyze the effect of external environments on positioning accuracy and positioning errors according to location and time were compared as well as the number of visible satellites and position dilution of precision by observatory were analyzed to verify a correlation with positioning error.

• Journal of Positioning, Navigation, and Timing
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• v.9 no.3
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• pp.191-205
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• 2020

Designing a new signal is essential in the development of a new Radio Navigation Satellite Service (RNSS) system. This paper introduces the signal design parameters and the figures of merit (FoMs) to be considered in designing a new RNSS signal, and then reviews their relationship in details. In addition, we show examples of the trade-off analysis between FoMs according to the signal design scenarios using an analytical simulation tool based on the relationship between the signal design parameters and the FoMs.

• Journal of Positioning, Navigation, and Timing
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• v.9 no.3
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• pp.249-259
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• 2020

China has deployed BDS along with the service of SBAS by 2020. Currently, the correction information for testing BDSBAS is provided through the BDS B1I signal. Many research on SBAS other than BDSBAS has been conducted in Korea. However, studies on BDSBAS are insufficient although Korea is included in both the coverage area of MSAS and BDSBAS. Therefore, it is necessary to continuously analyze the performance of MSAS and BDSBAS. In this paper, the performance of MSAS and BDSBAS in Korea, China, and Japan is analyzed in the aspect of positioning accuracy using the GNSS RINEX data provided by IGS. A Software platform is designed to analyze the performance of GPS-only, BDS-only, GPS/MSAS and BDS/BDSBAS. From the result, it can be concluded that the accuracy enhancement can be hardly seen when using the correction information of MSAS and BDSBAS in Korea

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1553-1557
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• 2005

High performance and reliability of the storage system to handle a very large amount of data has been become very important. Many techniques have been applied on the various application systems to establish very large capacity storage that satisfy the requirement of high I/O speed and physical or logical failure protection. We applied RAID and LVM to construct a storage system for the global data center which needs a very reliable large capacity storage system. The storage system is successfully established and equipped on the latest Linux application server.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.11
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• pp.1034-1039
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• 2012

In this paper, a structure of precise positioning based on satellite navigation system is proposed. The proposed system is consisted with three parts, range domain filter, navigation filter and position domain filter. The range domain filter generates carrier phase-smoothed-Doppler and Doppler-smoothed-code measurements. And the navigation filter calculates position and velocity using double-differenced code/carrier phase/Doppler measurements. Finally, position domain filter smooth position error, and it means enhancement of positioning performance. The proposed positioning method is evaluated by trajectory analysis using precise map date. As a result, the position error occurred by multipath or cycle slip was reduced and the calculated trajectory was in true lane.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.2
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• pp.183-189
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• 2011

An alignment algorithm for strapdown inertial navigation systems is proposed, in which the psi angle error model is utilized. The proposed alignment algorithm is derived from the Psi angle error model which has been widely used in real-time navigation systems. The equation for expecting steady state alignment error is also derived. The proposed algorithm was verified through real-time experiments. Experimental results show that the proposed algorithm can be used in the inertial navigation system and GNSS/INS integrated navigation system to get an initial attitude of the vehicle.

• International Journal of High-Rise Buildings
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• v.5 no.3
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• pp.205-211
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• 2016

This paper addresses the key technologies for supertall building construction based on the Lotte World Tower project in Korea. First, the mega-mat foundation construction technologies are shown, including ultra-low heat concrete, heat of hydration control programs, and the logistics plan. Then, high strength concrete technologies of 50~80 MPa are introduced and discussed within the context of the highest pumping record in Korea at 514.25 meters. Structural design concepts of gravity load and lateral force resistance systems are introduced, along with surveying systems using GNSS and temporary installation plans of special heavy equipment like tower cranes, hoists, and high pressure concrete pumps. If it is possible to coordinate these key technologies and others, optimizing for the building's design and construction, supertall building construction can be successfully completed.

• Smart Structures and Systems
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• v.17 no.5
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• pp.743-751
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• 2016

An ongoing research project is devoted to the design and implementation of a satellite based asset tracking for supporting emergency management in crisis operations. Due to the emergency environment, one has to rely on a low power consumption wireless communication. Therefore, the communication hardware and software must be designed to match requirements, which can only be foreseen at the level of more or less likely scenarios. The latter aspect suggests a deep use of a simulator (instead of a real network of sensors) to cover extreme situations. The former power consumption remark suggests the use of a minimal computer (Raspberry Pi) as data collector.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.299-302
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• 2010

GPS를 이용하여 고정밀도의 위치정보를 얻기 위해서는 가시위성의 기하학적 배치가 매우 중요한 요소로 작용되며 이 척도가 DOP라고 불리는 계수이다. 본 논문에서는 향후 많은 항법위성이 생길 경우 통합방식에 의해 원하는 위성을 선택함으로서 고의적인 재밍에 대한 대책 및 위치정보의 정밀도 향상 측면에서 매우 유용할 것으로 판단되어 첫 단계로 GPS 와 GLONASS의 통합 시스템 구축시 정밀도의 근간을 이루는 DOP 향상에 대하여 연구하였다. 데이터 분석결과 단독 GPS 사용시 보다 통합 GNSS 시스템이 0.3 ~ 0.8 정도의 우수한 GDOP 정보를 얻을 수 있었다. 따라서 이는 GDOP 뿐만이 아니라 결과적으로 고정밀도의 위치정보를 얻을 수 있음을 확인하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.10a
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• pp.401-402
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• 2013

GNSS Chipse equipped second generation LEO and GEO COSPAS SARSAT enabled EIPRIRB for fast search and rescue service in distress sirtuation was developed, certified, commercialized, exported successfully.