• 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.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.3
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• pp.217-223
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• 2004

In order to improve real-time positioning accuracy, a number of methods have been tested and one of those is the inverted RTK(Real-time kinematic) that gives a precise positioning by handling carrier phase measurements. For the inverted RTK positioning, it needs the L1 phase measurement at least for 1～2 minutes and the additional reference stations/communication system and a data processing server are required. The L1 code and carrier phase measurements for real-time application are used simultaneously and then Kalman filter is applied to estimate integer ambiguities. Double differenced integer ambiguities are resolved by utilizing the FARA(Fast Ambiguity Resolution Approach). In this paper, we propose the method to improve the positioning accuracy and performed the field tests for several baselines from DAEJ reference station in KAO(Korea Astronomy Observatory).

• IEMEK Journal of Embedded Systems and Applications
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• v.18 no.2
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• pp.75-80
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• 2023

Unmanned drone stations for automatic charging have been developed in order to overcome the flying time limitation of rotary wing drones. Since the drone stations is an unmanned operating system, each of the drones will be required to have a high degree of landing accuracy. Drone precision landing has been mainly studied depended on image processing technologies, but the image processing systems make several problems, such as the mission weight, the drone cost, and the development complexity increases, and the flight time decrease. Thus, this paper researched accuracy of precision landing based on RTK (real time kinetics) for rotary wing drones. For the experiments of RTK based precision landing, a drone repeatedly performed three missions. The survey accuracies of the RTK about missions respectively were set as 0.3, 0.2, and 0.1 meters. Each mission has one take-off point, two way-points and one landing-point, and was repeated ten times. The experiment results revealed landing error distance means of around 0.258, 0.12 and 0.057 meters on each of RTK setting.

• Electronics and Telecommunications Trends
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• v.38 no.3
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• pp.11-19
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• 2023

Drones, which were early operated by remote control, have evolved to enable autonomous flight by combining various sensors and software tools. In particular, autonomous flight of drones was possible since the application of GNSS-RTK (global navigation satellite system with real-time kinematic positioning), a precision satellite navigation technology. For instance, unmanned drone delivery based on GNSS-RTK data was demonstrated for pizza delivery in Korea for the first time in 2021. However, the vulnerabilities of GNSS-RTK should be overcome for delivery drones to be commercialized. In particular, jamming in the navigation system and low positioning accuracy in urban areas should be addressed. Solving these two problems can lead to stable flight, takeoff, and landing of drones in urban areas, and the corresponding solutions are expected to establish a hybrid positioning technology. We discuss current trends in hybrid positioning technology that can either replace or complement GNSS-RTK for stable drone autonomous flight.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.04a
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• pp.113-117
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• 2004

Such social structures as bridges, buildings, dams and towers have been transformed by their own load or fundamental ground. They have been behaved by other external causes. These regular or irregular behaviors threaten to do their users safety. Therefore, to monitor the load of the structures or reaction shown by them could help to verify their behaviors. RTK GPS allows the use of a static base station and remote rover unit to allow for data collection within several seconds and in real time. It is useful for monitoring the behaviors of massive structures like bridges. In this Study, Among GPS methods, we used RTK GPS to analyze the precision of monitoring and then on the basis of it, we developed a monitoring system using RTK GPS when measured the behavior of main tower of a suspension bridge by using RTK GPS. Comparing a deviation between observation values, X axis was 1mm, Y axis was 1mm and Z axis 2.2mm. It turned out that it was possible to monitor and measure structures by RTK GPS.

• Journal of Korean Neurosurgical Society
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• v.55 no.1
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• pp.57-60
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• 2014

Rhabdoid tumor of the kidney (RTK) is a rare malignancy in infancy. Central nervous system involvement in RTK is already known. However, solitary spinal metastasis in RTK has been hardly reported. The authors report a case of metastatic RTK to spine causing paraplegia in an 8-month-old girl. Since the patient was young, the diagnosis of spine metastasis was delayed until paraplegia was seen after radical nephrectomy. Thorough neurological examination should be performed for early diagnosis of spinal metastasis in young patients with RTK. If there are any abnormal signs in neurologic examination, magnetic resonance images of brain and spine are recommended.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.05b
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• pp.791-794
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• 2003

자동화 컨테이너터미널은 ATC(Automated Transfer Crane)와 AGV(Automated Guided Vehicle)와 같은 자동화 운송 장비를 사용하는 컨테이너터미널이다. 이러한 자동화 컨테이너터미널의 핵심은 생산성을 향상시키기 위한 효율적인 장비 운영이 결정적인 역할을 한다. 본 논문에서는 AGV의 이동 위치 결정을 위한 RTK-GPS(Real Time Kinematic-Global Positioning System) 위치 정보 전송 및 운용 방법에 대해서 연구하였다. 이를 위해서 기존의 무선모뎀을 이용한 RTK-GPS 전송 방법을 무선 LAN(Local Area Network) 환경에서 RTK-GPS 위치 정보 전송 방법에 대해서 제안하고, AGV 이동 위치 결정 및 계산을 실험하였다.

• Journal of Positioning, Navigation, and Timing
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• v.10 no.4
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• pp.253-262
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• 2021

Global Navigation Satellite Systems (GNSS) based precise positioning using Real Time Kinematic (RTK) technique has been proposed as an enabler of the formation operation of moving vehicles. In RTK methods, the integer ambiguity of GNSS carrier phase measurements must be resolved. Although there have been many proposed algorithms for the integer ambiguity resolution, the widelane combination of carrier phase measurements and LAMBDA methods have gained the most popularity in literatures when dual frequency GNSS measurements were used. In this paper, we evaluated five alternative methods to determine relative positions of moving base and rover receivers; the round-off scheme of widelane carrier phase, instant least-squares and Kalman filter-based LAMBDA with widelane carrier phase, instant least-squares and Kalman filter-based LAMBDA with dual frequency measurements. The paper presented the performance of each method using flight test data, which showed their strength and weakness in the aspects of time-to-first-fix, ambiguity resolution success ratio, and relative position errors. Based on that, we provided practical recommendations of RTK operations for moving vehicles.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2002.10a
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• pp.79-82
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• 2002

• 한국지형공간정보학회:학술대회논문집
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• 2003.09a
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• pp.189-194
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• 2003