• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.151-155
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• 2002

In this paper, interference effects between NGSO and HAPS analyze into two cases. One is HAPS interference effect into NGSO, another is NGSO interference effect into HAPS. First, same case of number of users for LEO and HAPS interference received to LEO mobile station are over the -8.82dB. But in case of 1/10 and 1/100, I/N values are lowest 16.9dB and -20.3dB respectively. In case of interference received to HPAS mobile station, as LEO is 87$^{\circ}$, if the HAPS and LEO users is same, interference criterion over the 2200 users. but in the case of 1/10 and 1/100 of LEO is HAPS users, we don't know over the interference criterion. In accordance with, for reduce to effects of interference important suitable establishment of transmission power, number of users and cell radius of two system.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.3
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• pp.433-440
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• 2022

High Altitude Long Endurance(HALE) solar powered UAV is the vehicle that flies for a long time as solar power energy sources. It can be used to replace satellites or provide continuous service because it can perform long-term missions at high altitudes. Due to the property of the mission, it is very important for HALE solar powered UAV to have maximum flight time. It is required for mission performance to fly at high altitudes continuously except a return for temporary maintenance. Therefore mission availability time analysis is a critical factor in the commercialization of HALE solar powered UAV. In this paper, we presented an analytic model and logic for available time analysis based on the design parameters of HALE solar powered UAV. This model can be used to analyze the possibility of applying UAV according to the UAV's mission in concept design before the UAV detail design stage.

• Journal of Advanced Navigation Technology
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• v.6 no.1
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• pp.10-16
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• 2002

High altitude platform station(HAPS) is being developed actively in some countries as well as Korea. At the same time Resolution 734 was adopted in WRC-2000 to study the sharing of HAPS into the existing fixed services in the bands above 3GHz. As one of the sharing studies, interferences between HAPS and radio-relay stations should be analyzed by dividing into two cases, the one is the interference effects of HAPS system into radio-relay stations and on the contrary, the other that of radio-relay stations into HAPS system. Since the former case had been already studied, only the latter case will be focused on this paper. Analysis result shows that the coordination distance must be needed above 100 km when the trendline of radio-relay is located vertical to HAPS service area and the transmitting power is -50 dBW/MHz.

• Journal of Aerospace System Engineering
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• v.12 no.1
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• pp.35-41
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• 2018

Unmanned Aerial Vehicles (UAV) have been used for various purposes in multiple fields, such as observation, communication relaying, and information acquisition. Nowadays, UAVs must have high performance in order to acquire more precise information in larger amounts than is now possible while performing for long periods. At present, domestically, a high-altitude long-endurance UAV (HALE UAV) for long-term flight in the stratosphere has been developed in order to replace some functions of the satellite. In this study, as a part of structural soundness evaluation of the aircraft structure developed for the HALE UAV, the structural soundness of the fasteners of the fuselage and tail is evaluated by calculating the margin of safety(M.S). The result confirms the validity of the design of the fasteners in the aircraft structure of the UAV.

• Journal of Advanced Navigation Technology
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• v.7 no.1
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• pp.22-29
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• 2003

In this paper, we analyze the interference effects between NGSO(Non-Geostationary Orbit) and HAPS(High Altitude Platform System) by dividing into two cases. The one is interference effects of HAPS into NGSO, the another is the interference effects of NGSO into HAPS. At the result, we canknow the interference effect into NGSO mobile station is the highest when position of NGSO is $95^{\circ}$. In this case, we can also know the interference effects from both HAPS and NGSO exceed interference criteria when the number of users are more than 20. And, in the case of the interference effect into HAPS mobile station, we can know it is the highest when elevation angle of NGSO is $87^{\circ}$, and the interference effects from both NGSO and HAPS exceed interference criteria when the number of users is more then 10. Moreover, the interference effect is the minimum, when elevation angle of NGSO is $64^{\circ}$, at this time, in case that the number of users of NGSO equal to the number of user of HAPS, the interference effects exceed interference criteria when the number of users is 190.