• Journal of Advanced Navigation Technology
• /
• v.24 no.6
• /
• pp.508-514
• /
• 2020

Geofence defines the area that UAS should not enter or exit to ensure the safety of their operations, and is considered as one of critical capabilities of the UTM (UAS traffic management) system. In this study, a geofence simplification method using modified perpendicular algorithm is proposed. The performances of the proposed geofence simplification method were evaluated with actual building data, and the evaluation results confirmed that the number of vertices can be effectively reduced while minimizing the spatial size of the geofence.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.29 no.2
• /
• pp.94-99
• /
• 2021

UTM is an air traffic management ecosystem under development for autonomously controlled operations of UAS by the FAA, NASA, other federal partner agencies, and industry. They are collaboratively exploring concepts of operation, data exchange requirements, and a supporting framework to enable multiple UAS operations beyond visual line-of-sight at altitudes under AGL 500ft in airspace where air traffic services are not provided. Minimum Safe Altitude is a generic expression, used in various cases to denote an altitude below which it is unsafe to fly owing to presence of terrain or obstacles. The European drone regulation mentions that the UAS is maintained within 120 metres from the closest point of the surface of the earth during flight, except when overflying an obstacle. This study attempted to develop a minimum flight altitude database system. Based on domestic and international rules and regulations on setting the minimum flight altitude it is expected that it can be applied to the operation of aircraft and unmanned aerial system in UTM environments for specific area in Korea.

• International Journal of Advanced Culture Technology
• /
• v.8 no.1
• /
• pp.173-181
• /
• 2020

This study examines whether unmanned aircraft systems (UAS) operated in the context of UAS traffic management (UTM) can be properly operated in its flight environment. In detail, this study examines the influencing navigation factors affecting UASs during flight and examines factors affecting the navigation of UASs under UTM. After deriving various factors affecting navigation, their importance are determined by applying the analytic hierarchy process technique, and the important influencing factors are examined. For low-altitude UAS navigation, errors are classified into navigation-system and flight-technical errors, and a hierarchy is constructed for their sub-factors affecting the influencers. Through this, influencing factors for precise navigation of low-altitude UAS are analyzed, and high importance items are identified.

• Journal of Advanced Navigation Technology
• /
• v.26 no.6
• /
• pp.448-455
• /
• 2022

In this study, when establishing a UTM(UAS Traffic Management) system, a corridor must be set to separate the flight distance between unmanned aerial vehicles, and the size of the corridor was calculated in consideration of TSE(Total System Error). The flight data of the straight section and the turning section were collected using a hybrid vertical take-off and landing unmanned aerial vehicle. The flight data were derived from the TSE using the SQSM(Scalar Quantity Summation Method) method, and the impact on the straight and turning sections was analyzed by calculating in detail by NSE(Navigation System Error) and FTE(Flight Technical Error). The corridor size was calculated by referring to the TSE analysis results and PBN (Performance-based Navigation) manual.

• Journal of Advanced Navigation Technology
• /
• v.24 no.6
• /
• pp.471-478
• /
• 2020

In this paper, we develop the ground risk model of unmanned aerial vehicle (UAV) operation to quantify the ground risk when the UAV falls to the ground during the intended operation in case of UAV failure. The ground risk is computed by using the UAV failure probability, the probability of impact a person when UAV falls to the ground, the probability of fatality when UAV strikes the person. We mathematically derive each probability to evaluate the ground risk of UAV operation. Also, the population density map, building to land ratio map, car traffic database is used to estimate the number of people exposed to collision with UAV. Finally, we assumed the operations of a UAV with two paths in Daejeon city and evaluate the ground risk of each UAV operations.

• The Korean Journal of Air & Space Law and Policy
• /
• v.28 no.1
• /
• pp.3-54
• /
• 2013

Nowadays, major advanced countries in aviation technology are putting their effort to develop commercial and civil Unmanned Aircraft System(UAS) due to its highly promising market demand in the future. The market scale of commercial and civil UAS is expected to increase up to approximately 8.8 billon U.S. dollars by the year 2020. The usage of commercial and civil UAS covers various areas such as remote sensing, relaying communications, pollution monitoring, fire detection, aerial reconnaissance and photography, coastline monitoring, traffic monitoring and control, disaster control, search and rescue, etc. With the introduction of UAS, changes need to be made on current Air Traffic Management Systems which are focused mainly manned aircrafts to support the operation of UAS. Accordingly, the legislation for the UAS operation should be followed. Currently, ICAO's Unmanned Aircraft System Study Group(UASSG) is leading the standardization process of legislation for UAS operation internationally. However, some advanced countries such as United States, United Kingdom, Australia have adopted its own legislation. Among these countries, United States is most forth going with President Obama signing a bill to integrate UAS into U.S. national airspace by 2015. In case of Korea, legislation for the unmanned aircraft system is just in the beginning stage. There are no regulations regarding the operation of unmanned aircraft in Korea's domestic aviation law except some clauses regarding definition and permission of the unmanned aircraft flight. However, the unmanned aircrafts are currently being used in military and under development for commercial use. In addition, the Ministry of Land, Infrastructure and Transport has a ambitious plan to develop commercial and civil UAS as Korea's most competitive area in aircraft production and export. Thus, Korea is in need of the legislation for the UAS operation domestically. In this regards, I personally think that Korea's domestic legislation for UAS operation will be enacted focusing on following 12 areas : (1)use of airspace, (2)licenses of personnel, (3)certification of airworthiness, (4)definition, (5)classification, (6)equipments and documents, (7)communication, (8)rules of air, (9)training, (10)security, (11)insurance, (12)others. Im parallel with enacting domestic legislation, korea should contribute to the development of international standards for UAS operation by actively participating ICAO's UASSG.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.28 no.4
• /
• pp.47-54
• /
• 2020

This study carries out a basic study of ways to calculate navigation errors for aircraft operating in the unmanned aerial system traffic management(UTM). Recently, research by UTM has been carried out both at home and abroad, along with the initial study of system definitions at the basic stage, operational techniques of the aircraft, and the practicality of the concept of necessary operations at the actual operational stage. This study presented after a review the factors that should be considered for the calculation of navigation errors among the factors that examine whether the actual low altitude aircraft can operate properly within UTM during its actual operation and the need to apply them in practice.

• Journal of Advanced Navigation Technology
• /
• v.26 no.2
• /
• pp.91-98
• /
• 2022

Unmanned aircraft system traffic management (UTM) service for the safe operation of unmanned aerial vehicles (UAV) such as drones using commercial communication networks such as long-term evolution (LTE) and 5G in low-altitude areas of 150m or less is being studied in several countries. In this paper, whether it is possible to secure three-dimensional (3D) coverage for UTM service using the existing LTE cellular network for terrestrial usersis analyzed through simulations. The practicality in the real environment is confirmed by performing performance analysis in the actual topographical environment and the LTE base station layouts in Korea. According to the analysis results, as the altitude increases, the number of line-of-sight (LOS) interference base stations increases, resulting in a worse signal to interference plus noise ratio (SINR), but coverage is secured except for the limited areas within 150m. was confirmed to be possible. In addition, it is confirmed that a significant proportion of outage areas could be reduced by placing a small number of additional base stations for the outage area.