Aviation, Space and Ocean : Considerations on In-Flight Validation for KASS
구본수 Bon Soo Koo , 이은성 Eun Sung Lee , 남기욱 Gi Wook Nam , 강재민 Jae Min Kang , 조정호 Jeong Ho Cho , 홍교영 Gyo Young Hong
19(3) 175-181, 2015
구본수 Bon Soo Koo , 이은성 Eun Sung Lee , 남기욱 Gi Wook Nam , 강재민 Jae Min Kang , 조정호 Jeong Ho Cho , 홍교영 Gyo Young Hong
DOI: JANT Vol.19(No.3) 175-181, 2015
Method establishment needs for recent shortening the flight path, fuel reduction, reduction of the flight delay time , increase of the route capacity like as relieve congested airspace and solving future demand. However, As the existing conventional navigation systems is impossible to be resolved. Hereupon, SBAS has been developed with using the GNSS. ICAO has recommended that SBAS need to be operated with aircraft operation from 2025, korea is also developing KASS in accordance with the recommendation. In this paper, before the 2022 KASS will be completed, KASS can be expected using for flight test and inspection as analyzing KASS flight test and relative specifications.
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Aviation, Space and Ocean : Design and Implementation of Automatic Dependent Surveillance - Broadcast Server System
조태환 Taehwan Cho , 김강희 Kanghee Kim , 김진혁 Jinhyuk Kim , 최상방 Sangbang Choi
19(3) 182-191, 2015
조태환 Taehwan Cho , 김강희 Kanghee Kim , 김진혁 Jinhyuk Kim , 최상방 Sangbang Choi
DOI: JANT Vol.19(No.3) 182-191, 2015
The automatic dependent surveillance - broadcast (ADS-B) system which is a core system of aviation system block upgrade is designed and implemented. The ADS-B system consists of the 4 blocks and 10 units, and filtering algorithm is applied to the implemented ADS-B system. To evaluate a performance of the implemented ADS-B system, real aircraft position data is used and compared reliable radar data. The comparison results show that average position difference of 99.57 m. In addition, comparisons of aircraft position data between the implemented ADS-B system employing filtering algorithm and the conventional ADS-B system under various situations are carried out, such as aircraft turning, taking off, landing, and cruising. The comparison results show that average position difference of 8.02 m.
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Aviation, Space and Ocean : Comparison of ILS and GBAS Through Flight Test in Taean Aerodrome and Kimpo Airport
구본수 Bon Soo Koo , 김우리얼 Woo Ri Ul Kim , 주요한 Yo Han Ju , 홍교영 Gyo Young Hong
19(3) 192-198, 2015
구본수 Bon Soo Koo , 김우리얼 Woo Ri Ul Kim , 주요한 Yo Han Ju , 홍교영 Gyo Young Hong
DOI: JANT Vol.19(No.3) 192-198, 2015
Since instrument landing system currently operating in most airports is operating in single-pass, it is not possible to accommodate a large number of aircraft. A satellite navigation system GBAS using a GNSS has been developed to solve these limitation when air traffic increases. GBAS is better than the ILS in position accuracy and capable of landing through multiple paths rather than a single path, the aircraft can perform varied landing procedures. In this paper, after we established a virtual ILS procedures at Taean Airfield in which ILS installation is impossible due to environmental requirements and airspace restrictions, flight test was performed by Cessna Skyhawk 172 to compare the virtual ILS procedures and curved approach procedure and the advantage of curved approach was confirmed.
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Navigation : An Analysis on the Real-Time Performance of the IGS RTS and Ultra-Rapid Products
김민규 Mingyu Kim , 김정래 Jeongrae Kim
19(3) 199-206, 2015
김민규 Mingyu Kim , 김정래 Jeongrae Kim
DOI: JANT Vol.19(No.3) 199-206, 2015
For real-time precise positioning, IGS provides ephemeris predictions (IGS ultra-rapid, IGU) and real-time ephemeris estimates (real-time service, RTS). Due to the RTS data latency, which ranges from 5 s to 30 s, a short-term prediction process is necessary before applying the RTS corrections. In this paper, the real-time performance of the RTS correction and IGU prediction are compared. The RTS correction availability for the GPS satellites observed in Korea is computed as 99.3%. The RTS correction is applied to broadcast ephemeris to verify the accuracy of the RTS correction. The 3D orbit RMS error of the RTS correction is 0.043 m. Prediction of the RTS correction is modeled as a polynomial, and then the predicted value is compared with the IGU prediction value. The RTS orbit prediction accuracy is nearly equivalent to the IGU prediction, but RTS clock prediction performance is 0.13 m better than the IGU prediction.
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Navigation : An Analysis of Reference Station Distribution Impact on KASS UDRE Performance
윤영선 Youngsun Yun
19(3) 207-216, 2015
윤영선 Youngsun Yun
DOI: JANT Vol.19(No.3) 207-216, 2015
Since the distribution of SBAS reference stations is one of the most important factors that affect the system performance, the effects of the distribution should be analyzed carefully from the beginning of the program to develop the system conforming to given performance requirements. The reference stations of KASS, the Korean SBAS, are planned to be installed only inside South Korea, which limits the number and area of those. It differentiates KASS from others that have much larger sites. In this paper, the author analyzes the performance impact on UDRE and δUDRE for GPS and GEO due to the limitations by a series of simulations, which showed that the UDRE performance depends on the diversity of the reference station distribution and the impact on the GEO UDRE is significant. The paper concludes by providing KASS design and development considerations to minimize the possible performance risks due to the limitations of KASS reference station distribution.
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Aviation Communication Technique: Design and Implementation of Mobile Network Based Long-Range UAV Operational System for Multiple Clients
박성현 Seong Hyeon Park , 송준범 Joon Beom Song , 노민식 Min Shik Roh , 송우진 Woo Jin Song , 강범수 Beom Soo Kang
19(3) 217-223, 2015
박성현 Seong Hyeon Park , 송준범 Joon Beom Song , 노민식 Min Shik Roh , 송우진 Woo Jin Song , 강범수 Beom Soo Kang
DOI: JANT Vol.19(No.3) 217-223, 2015
This paper describes the design and implementation of a network system for UAV for multiple clients that enables long-range operation based on a commercial mobile network. A prototype data modem is developed with a commercial embedded M2M module in order to provide an access to the mobile network. A central server with a database is constructed to record all of real-time flight and video data and communicate with a ground control system. A GCS is developed for the central control, the single UAV and the smart phone version to be used for different purposes. Performance tests were progressed for data delay, video frame rate and state of clients. Flight tests were also performed to verify the reliability of the modem with respect to altitude.
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Basic Technique for Navigation and Aviation : Unequal Gysel Power Divider Using External One Resistor
윤영철 Young Chul Yoon , 심석현 Seok Hyun Sim , 김영 Young Kim
19(3) 224-229, 2015
윤영철 Young Chul Yoon , 심석현 Seok Hyun Sim , 김영 Young Kim
DOI: JANT Vol.19(No.3) 224-229, 2015
In this paper, we derived the design equation and implemented the unequal Gysel power divider that is one external resistors using the ABCD parameters analysis. Conventional unequal Gysel divider is difficult to obtain the characteristics of isolation and return loss at between output ports because it can’t select a theoretical value of external resistor. To solve those problems, we design the new unequal Gysel power divider with transmission lines and one external resistor that has the characteristics of conventional unequal Gysel divider. To validate this design method, we simulated and measured an 4: 1 unequal Gysel power divider at the center frequency 1 GHz. The measured performances agreed well with the simulation results.
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Basic Technique for Navigation and Aviation : Study on the Between the Grounding Resistance and Grounding Electrode using Mesh Grounding Electrodes and a Shielding Panel
이충식 Chung Sik Leeg , 조문택 Moon Taek Cho , 나승권 Seung Kwon Na
19(3) 230-236, 2015
이충식 Chung Sik Leeg , 조문택 Moon Taek Cho , 나승권 Seung Kwon Na
DOI: JANT Vol.19(No.3) 230-236, 2015
In this paper, the electric potential of electrode surface is investigated by assuming them as two dimensional sets of point current sources. And, the simulated water tank is manufactured as a reduced scale of the earth. Henceforth, the adequate model electrode for test is decided to decrease experimental errors relevant to the limitation of the size of the water tank. The one of important things of this work, the deduction method of the potential interference factor is proposed, which used as the criterion of the potential interference according to the shape of conductors and the laying conditions, when multiple grounding conductors are situated at the same resistance grounding area. Also, the validity of this theory is verified from a numerical simulation of the grounding electrode to be used in experiments, and this study is realized by the verified theory and the simulated experiments.
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Basic Technique for Navigation and Aviation : Performance Measurement of the Wireless Charging Devices Using Eletromagnetic Induction Techniques
류다운 Daun Ryu , 김영현 Young Hyun Kim , 구경헌 Kyung Heon Koo
19(3) 237-243, 2015
류다운 Daun Ryu , 김영현 Young Hyun Kim , 구경헌 Kyung Heon Koo
DOI: JANT Vol.19(No.3) 237-243, 2015
This paper presented the design of wireless power transfer (WPT) system using electromagnetic induction techniques and analysed WPT efficiency. Also, we presented the optimum coil condition by measuring the efficiency variation according to some receiving coil parameter changes. Voltage change is measured by receiving coil position for the designed transmitting and receiving circuit. Voltage change according to inductance variation at the same position and charging time are compared at the same environment by using a developed application program to realize an optimum WPT system. Developed wireless power transfer system using electromagnetic induction techniques uses 125 kHz. It takes 16 minutes by using wired charger, and 23 minutes by using wireless charger for charging from 50% to 60% charging status.
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Basic Technique for Navigation and Aviation : An Analysis of the HEMP Interference Effect in OFDM System
성윤현 Yun Hyeon Seong , 장은영 Eun Young Chang , 윤석범 Seok Beom Yoon
19(3) 244-249, 2015
성윤현 Yun Hyeon Seong , 장은영 Eun Young Chang , 윤석범 Seok Beom Yoon
DOI: JANT Vol.19(No.3) 244-249, 2015
High-altitude electromagnetic pulse (HEMP) is generated from a nuclear burst at high altitudes above the Earth, the electromagnetic fields reach the ground nearly simultaneously with regard to the operation time of systems. The aim of this analysis is to inquire about HEMP characteristics and to analyze about effect in orthogonal frequency division multiplexing (OFDM) system. Specifically, HEMP characteristics are classified field sources, spatial coverage, time domain behavior, frequency spectrum and field intensities in this study. Bits error rate (BER) of the receiver with the software simulation is confirmed for the HEMP effect. Q-factor made a difference about interference duration by transfer characteristics of system. When Q factor is smaller, the recovery time from HEMP interference is short. To the contrary, if the Q factor is larger, the recovery duration is lasted longer by 300-600%.
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Basic Technique for Navigation and Aviation : A Study on the Hybrid Arc Extinguishing Mechanism of the DC Circuit Breaker
주남규 Nam Kyu Joo , 김남호 Nam Ho Kim
19(3) 250-256, 2015
주남규 Nam Kyu Joo , 김남호 Nam Ho Kim
DOI: JANT Vol.19(No.3) 250-256, 2015
Digital load is increasing suddenly for various reasons, such as easy control and management. Accordingly, a consumption pattern of load is becoming DC. However, the power supply is supplied by AC power. The load power supply substantially needs DC power. AC power has to be converted to DC power. Renewable energy sources like solar, wind and fuel cells are DC power generation, but the transfer needs to through by AC power, thus DC power has to be converted to AC power. Resultantly, a multi-stage conversion loss is constantly increasing. The power distribution system of DC-based is required for effective use of these energy sources. This requires a DC load, as well as is necessary to develop DC breaker. This study is expect for system and equipment for reliable DC power distribution through the study of the arc extinguish technology for direct current a hybrid arc extinguishing technology with permanent magnets technology.
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Application and Convergence Technique : A Study on the Iptables Ruleset Against DoS Attacks
정성재 Sung Jae Jung , 성경 Kyung Sung
19(3) 257-263, 2015
정성재 Sung Jae Jung , 성경 Kyung Sung
DOI: JANT Vol.19(No.3) 257-263, 2015
Although a variety of preparation methods for DoS attacks and DDoS attacks are presented, it is still being exploited, the vulnerability with networks and protocols. In particular, When was built environment that can be used anywhere in the Internet, Internet of Things is entering era. Thus, the conventional computer, as well as household appliances, etc. DoS attack targets or are likely to do the attacker role is increasing. In this paper, we first find out about the type and characteristics of DoS attacks. Open source operating system, Linux has iptables that packet filtering tool and firewall programs. Using iptables to set the policy ruleset against DoS attacks.
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