• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.1C
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• pp.131-137
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• 2009

Binary offset carrier (BOC) signal synchronization is one of the most important steps to recover the transmitted information in global navigation satellite systems (GNSS) including Galileo and global positioning system (GPS). Generally, BOC signal synchronization is based on the correlation between the received and locally generated BOC signals. Thus, the multiple side-peaks in BOC autocorrelation are one of the main error sources in synchronizing BOC signals. Recently, a novel correlation function with reduced side-peaks was proposed for BOC signal synchronization by Julien [8]; however, Julien's correlation function not only still has the side-peaks, but also is only applicable to sine phased BOC(n, n), where n is the ratio of the pseudo random noise (PRN) code rate to 1.023 MHz. In this paper, we propose a new correlation function for BOC signal synchronization, which does not have any side-peaks and is applicable to general types of BOC signals, sine/cosine phased BOC(kn, n), where k is the ratio of a PRN chip duration to the period of a square wave sub-carrier used in BOC modulation. In addition, an efficient correlator structure is presented for generating the proposed correlation function.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.9
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• pp.2124-2130
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• 2014

The standard for DGPS reference station system defined by RTCM is in the current version of 1.2. This standard currently supports only GPS of the United States. However, the current operating GNSS satellite consisted of not only GPS, but also GALILEO of Europe, GLONASS of Russia, QZSS of Japan, BeiDou of China and so on. Therefore, the existing standard is not able to support them. Accordingly, a new standard in the version of RTCM's RSIM 1.3 is established in order to provide correctional services to GNSS satellites. In this paper, the version of RSIM 1.3 is analyzed and the software for DGNSS reference station architecture supporting the version of RSIM 1.3 is designed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.5
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• pp.74-83
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• 2004

The carrier phase measurements from GPS and GLONASS have different characteristics and therefore, have to be processed with different methods to provide precise positions or attitudes. In this contribution, at first, a measurement model is derived which can be used to not only GLONASS only applications but also both GPS and GLONASS applications. And then an error analysis of the proposed method performed using the derived model to derive analytic relationships between GDOP, PDOP and RGDOP. Finally, an integer ambiguity resolution method which was used in GPS is expanded to GPS and GLONASS. The proposed results can be directly applied to the design and analysis of GLONASS receiver and application programs. Furthermore, it is expected that the suggested method can also be effectively applied to combine the characteristically different measurements from the future satellite navigation systems such as GPS modernization, Galileo and QZSS.

• Journal of Advanced Navigation Technology
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• v.26 no.6
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• pp.412-417
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• 2022

In this paper, multi-GNSS network RTK MAC correction generation software developed based on MATLAB GUI is introduced. The software was developed as a post-processing software based on simulation data to evaluate the feasibility of an algorithm for generating correction for multi-GNSS including GPS, GLONASS, and Galileo. As a result of software operation, network RTK correction for each system of multi-GNSS is output in MATLAB file format. In this paper, to evaluate the performance of the developed software, the residual error was analyzed after applying the correction generated through the software to the user. As a result of the analysis, it was confirmed that effective network RTK correction could be generated by confirming that the residual errors of users were maintained at 10 cm or less.

• Electronics and Telecommunications Trends
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• v.23 no.4
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• pp.137-146
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• 2008

위성항법수신기는 항법위성(GPS)들이 현재 위치와 시간이 담긴 전파신호를 지상으로 송신하면, 이런 신호를 받아 전파가 도달하기까지 걸린 시간을 계산해 자신의 현재 위치를 파악하게 된다. 경도와 위도, 높이를 동시에 파악하기 위해서는 3개 위성신호가 요구되고, 위성간 시간 오차를 제거해 위치 측정의 정확도를 높이기 위한 신호용으로 또 하나의 위성이 필요해 4개 위성이 요구된다. 항법의 형태는 육표기반 항법, 천체기반 항법, 센서기반 항법, 무선기반 항법 및 위성기반 항법으로 분류되며 그 중 전역이고 간섭 영향 및 재밍(jamming)이 어려우며 정확도 측면에서 우수한 위성항법시스템에는 GPS(미국), GLONASS(러시아)가 운용중이고, Galileo(유럽연합), COMPASS(중국), QZSS(일본), IRNSS(인도)이 개발중이다. 위성항법시스템 다원화에 따라 위성항법 수신기 기술도 이중주파수처리 및 타 시스템과의 호환성 제공이 요구되는바, 본 논문에서는 위성항법 수신기 기술 동향을 소개하고자 한다.

• Proceedings of the KIEE Conference
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• 2007.10c
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• pp.235-237
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• 2007

This paper inspected about the application of transportation and the character of GPS&Galileo using the basis of GNSS. In the paper, searched the present condition of study which applied foreign GNSS in the railway and drew the applicable field which is corresponded with the railway environment. It also described about the embodiment and prospection of system and presented the direction of study on the basis of it.

• Bulletin of the Korean Space Science Society
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• 2008.10a
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• pp.22.4-22.4
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• 2008

The anomalous acceleration of Pioneer-10 and Pioneer-11 is known since 1992. These spacecrafts show the unexplainable acceleration near $10^{-7}\;cm/sec^2$ in the direction to the Sun. Later the unknown acceleration of the same order was found in the motion of Ulysses in its motion from the Jupiter to Mercury, and in the motion of Galileo, NEAR, Cassini, Rosetta, and Messenger at the flybys of these spacecrafts near the Earth. The possibility of unexplainable acceleration near $10^{-7}\;cm/sec^2$ was discussed also for stellar globular clusters and for galaxies. We propose the empirical formula for taking into account this acceleration and overview the predictions of this formula at cosmological scales. Several unknown observational effects are found. One of these effects is the anomalous redshifts in the clusters of galaxies. It was known previously only for small groups of galaxies. We show the existence of anomalous redshifts in the clusters of galaxies using the spectral observations of near one million galaxies from the SLOAN 5th data release.

• Journal of Positioning, Navigation, and Timing
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• v.6 no.1
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• pp.35-41
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• 2017

Precise Point Positioning (PPP) method is based on dual-frequency data of Global Navigation Satellite Systems (GNSS). The recent multi-constellations GNSS (multi-GNSS) enable us to bring great opportunities for enhanced precise positioning, navigation, and timing. In the paper, the multi-GNSS PPP with a combination of four systems (GPS, GLONASS, Galileo, and BeiDou) is analyzed to evaluate the improvement on positioning accuracy and convergence time. GNSS observations obtained from DAEJ reference station in South Korea are processed with both the multi-GNSS PPP and the GPS-only PPP. The performance of multi-GNSS PPP is not dramatically improved when compared to that of GPS only PPP. Its performance could be affected by the orbit errors of BeiDou geostationary satellites. However, multi-GNSS PPP can significantly improve the convergence speed of GPS-only PPP in terms of position accuracy.

• School Mathematics
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• v.4 no.1
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• pp.49-62
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• 2002

developed by solving practical problems and gradually formalized and abstracted. But school mathematics seemed to stress the formalized and abstracted mathematics. The same is the case with calculus. In particular, it appeared extremely in teaching of calculus. It caused hindrance of learning and indeed, many students had difficulties in teaming of calculus. Therefore this study investigates the various approaches of calculus teaching and the history of calculus which include approaches by Archimedes, Galileo, Newton, Leibniz and Weierstrass etc. This may offer the implication for calculus teaching and we can find the alternative on the method of calculus teaching in historico-genetic principle. Finally we suggest the direction of calculus teaching from this perspective in tile concrete.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.4
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• pp.425-430
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• 2016

Currently, start of the operation US GPS, the Russian Glonass, European Galileo, the Chinese Compass satellites for positioning are celebrating a true GNSS (Global Navigation Satellite System) generation. Korea is building advanced infrastructure such as a national network consisting of CORS (Continuously Operating Reference Station), VRS service for real-time precise positioning and perform continuous upgrading. However, the acquisition of geospatial information using the national infrastructure requires many steps and high dependence on foreign software part in this process. This study contributes to advanced construction technology of geospatial information by design of realtime GNSS surveying system. As a results, it has designed the surveying software that can effectively positioning realtime. Designed realtime surveying software can utilized in various fields.