• Journal of Satellite, Information and Communications
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• v.8 no.1
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• pp.40-44
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• 2013

In this paper, we describe on the position error of GBAS. In reality, there are many sources which make errors into the calculation of receiver position. It is well known that the DOP of GBAS is an important position error source and is dependent on the numbers and positions of the transmitters. Here, we develop an algorism to calculate the DOP of the GNSS with 2-line transmitters into Korean area. The result is useful to predict the DOP of the positions where transmitters and receivers are located.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.3
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• pp.403-408
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• 2008

The gyroscope is the sensor for detecting the rotation in inertial reference frame and constitute the navigation system together an accelerometer. As the inertial reference equipment for attitude determination and control in the satellite, the mechanical gyroscope has been used but it bring the disturbance for mass unbalance so the disturbance give a bad influence to the observation satellite mission because the mechanical gyroscope has the rotation parts. During the launch. The mechanical gyroscope is weak in vibration, shock and has the defect of narrow operating temperature range so it need the special design in integration. Recently the low orbit observation satellite for seeking the high pointing accuracy of image camera payload accept the FOG(Fiber Optic Gyro) or RLG(Ring Laser Gyro) for the attitude determination and control. The Ring Laser Gyro makes use of the Sanac effect within a resonant ring cavity of a He-Ne laser and has more accuracy than the other gyros. It need the 1000V DC to create the He-Ne plasma in discharge tube. In this paper, the design process of the High Voltage Power Supply for RLG(Ring Laser Gyroscope) is described. The specification for High Voltage Power Supply (HVPS) is proposed. Also, The analysis of flyback converter topology is explained. The Design for the HVPS is composed of the inverter circuit, feedback control circuit, high frequency switching transformer design and voltage doubler circuit.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1488-1490
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• 2008

The gyroscope is the sensor for detecting the rotation in inertial reference frame and constitute the navigation system together an accelerometer. As the inertial reference equipment for attitude determination and control in the satellite, the mechanical gyroscope has been used but it bring the disturbance for mass unbalance so the disturbance give a bad influence to the observation satellite mission because the mechanical gyroscope has the rotation parts. During the launch, The mechanical gyroscope is weak in vibration, shock and has the defect of narrow operating temperature range so it need the special design in integration. Recently the low orbit observation satellite for seeking the high pointing accuracy of image camera payload accept the FOG(Fiber Optic Gyro) or RLG(Ring Laser Gyro) for the attitude determination and control. The Ring Laser Gyro makes use of the Sanac effect within a resonant ring cavity of a He-Ne laser and has more accuracy than the other gyros. It need the 1000V DC to create the He-Ne plasma in discharge tube. In this paper, the design process of the High Voltage Power Supply for RLG(Ring Laser Gyroscope) is described. The specification for High Voltage Power Supply(HVPS) is proposed. Also, The analysis of flyback converter topology is explained. The Design for the HVPS is composed of the inverter circuit, feedback control circuit, high frequency switching transformer design and voltage doubler circuit.

• Journal of the Korean Institute of Navigation
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• v.17 no.2
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• pp.75-106
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• 1993

GMDSS(Global Maritime Distress and Safety system) is a new communication system for the distress and safety at sea which is utilizing the recent advancements in satellite communication and positioning system, digital communication system, computer and microelectronic technology, etc., and will completely substitute the current communication system by 1999. Although the improvements of education for producing qualified Radio Operators as well as the establi-shments of policy for accepting the system are required, the educational institutions and relating administ-rations have not yet prepared the rational and concrete schemes on the educational methods and accepting procedures for the system. In this study, as the result of analyzing the GMDSS, courses of training and relating data, the authors suggested principles for improving the course and contents of education and rational schemes for balan-cing the demand and supply of Radio Operators. The authors expect not only the consequences of this study can be utilized as reference materials for the instruction to ratio communication in the organs of education but also that the following effects can be obtained by the study. 1. Security of distress and safety communication system at sea by the establishment of relating regula-tions. 2. Rationalization of the management of radio communication at sea and improvement of the communi-cation system on the vessel. 3. Upgrading the quality of Radio Operators and presenting schemes for current qualified persons. 4. Activation of industry producing radio instruments. 5. Balance of the demand and supply of Radio Operators and development of shipping industry.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.11a
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• pp.73-74
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• 2019

We are developing a receiver that integrates eLoran and GNSS for navigation. The receiver shows similar performance to LORADD receiver in single navigation using Loran-C. In the case of GNSS navigation, the receiver uses GPS and GLONASS or GPS and BDS, so it has better navigation performance than the LORADD receiver using only GPS. Therefore, it is possible to expect better performance than the LORADD receiver in the integrated navigation which can complete the time synchronization between the chains later and obtaion the TOA. Loran data channel decoding function is implemented for eLoran navigation and the function of eliminating error factors such as interference is being implemented.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.06a
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• pp.144-145
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• 2014

IoT (Internet of Things) is connected to all things Internet-based people and things, things and objects that communicate information between said intelligent technologies and services. Shipping each of a variety of devices that act independently from each other, but, it is actively interlock with each other is not easy practically days. Ship it within the means of communication, the communication between the ship, the communication between ship and shore configuration, SAN (Ship Area Network), RFID/USN, broadband communications, satellite communications and IT technology to a variety of marine environments for the safe navigation the ship's safety management system for the configuration you want to discuss the plan.

• Journal of Advanced Navigation Technology
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• v.25 no.1
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• pp.78-83
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• 2021

Due to rapidly increasing air traffic congestion and airspace restrictions, the International Civil Aviation Organization (ICAO) is urging all aircraft to use SBAS by 2025, in order to implement Performance-based navigation to increase airspace capacity. In line with this, research and development of Korean-style SBAS, which reflects the characteristics of Korea's airspace environment, continues in Korea. Since there is no flight inspection procedure for performance testing and verification of SBAS in Korea yet, this paper analyzes FAA, ICAO Regulations, and laws enacted by the Ministry of Land, Infrastructure and Transport to derive essential evaluations and parameters of Korean SBAS, and presents the optimal design using RTK-DGPS as a position fixing system.

• 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 Navigation and Port Research
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• v.43 no.6
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• pp.429-436
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• 2019

The eLoran system is considered the best alternative because the vulnerability of satellite navigation systems cannot be resolved as perfect. Thus, South Korea is in the process of establishing a testbed of the eLoran system in the West Sea. To provide resilient navigation services to all waters, additional eLoran transmitters are required. However, it is difficult to establish eLoran transmitters because of various practical reasons. Instead, the positioning with NDGNSS/AIS source can expand the coverage and its algorithm with applying continuous waves is under development. Using the already operating NDGNSS reference station and the AIS base station, it is possible to operate the navigation system with higher accuracy than before. Thus, it is crucial to predict the performance when each system is integrated. In this paper, we have developed a simulation tool that can predict the performance of terrestrial integrated navigation system using the eLoran system, maritime NDGNSS station and the AIS station. The esitmated phase error of the received signal is calculated with the Cramer-Rao Lower Bound factoring the transmission power and the atmospheric noise according to the transmission frequency distributed by the ITU. Additionally, the simulation results are more accurate by estimating the annual mean atmospheric noise of the 300 kHz signal through the DGPS signal information collected from the maritime NDGNSS station. This approach can further increase the reliability of simulation results.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.19 no.1
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• pp.9-17
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• 2001

GPS is an efficient system in surveying and car navigation. but it is difficult to catch minimum number of satellite when it is hindered by obstacle such as city area. GLONASS system doesn't have perfect constellation yet, but it has many similarities with GPS system in principle of point positioning and signal system. so, it is expected to be much efficient when it is used with GPS system. For the purpose of this, the coordinates of GPS and GLONASS system, the quality of time and frequency was investigated, and the algorithm of point positioning was made. also, the efficiency of GPS/GLONASS combination was presented by analysing the precision of 3D point positioning using C/A code and Yuma satellite orbit information.