• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.11A
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• pp.1206-1212
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• 2007

International Civil Aviation Organization(ICAO) adopted VOR(Very high frequency Omni-Range) as an international standard air navigation system in 1949 and recommended every country to make use of it in formulating air route and guiding take-off and landing of an aircraft. VOR is quite a useful navigation system so that more than 2,000 VORs are currently installed all over the world including 39 in the Republic of Korea; however, VOR signal could be easily affected by its circumstance like a mountainous area because it provides navigation information to an aircraft through AM and FM of VHF carrier. There are two types of VOR which are defined according to a design methode. Therefore this study intends to investigate which type of VOR is suitable for mountainous area. For that purpose, the performance of each CVOR and DVOR is measured and analyzed by using an aircraft equipped with measuring instruments. The analyzed result will be applied and utilized in selecting the VOR type, so it could be a feasible solution of problem related to the VOR relocation due to its insufficient performance in the future.

• Journal of Advanced Navigation Technology
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• v.12 no.1
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• pp.1-7
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• 2008

International Civil Aviation Organization(ICAO) adopted VOR(Very high frequency Omni-Range) as an international standard air navigation system in 1949 and recommended every country to make use of it in formulating air route and guiding take-off and landing of an aircraft. VOR is quite a useful navigation system so that more than 2,000 VORs have been installed all over the world including 39 in Korea: however, VOR signal could be easily affected by its circumstance like a mountainous area because it provides navigation information through AM and FM of VHF carrier. Therefore this study intends to investigate how much VOR performance is affected by its circumstances. For this purpose, the performance of the 10 VORs influenced by 24 obstacles are measured and analyzed by using an aircraft equipped with measuring instruments. This study may give us a feasible solution of problems related to the VOR siting in the future.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.3A
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• pp.319-326
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• 2008

All over the world more than 2,000 VORs(VHF Omni-directional Ranges) including 39 in Korea are being operated for formulating air routes. But VOR reveals some difficulties in cost and time when relocating already an installed one due to its poor performance from the interference by its geometrically surrounding obstacles. DVOR(Doppler VOR) which is more popular than CVOR(Conventional VOR) has huge antennas and make it very difficult to assume a sufficient number of proper site candidates for permanent installation. This paper develops an efficient method for predicting proper site of DVOR installation by isolating transmitter from sideband antennas and counterpoise, making the transmitter easily moveable and verifying the performance of DVOR only with a transmitter and an antenna. The method was tested with a real flight measurement for DVOR performance around Gwangju Airport in Korea.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.20 no.2
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• pp.13-17
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• 2012

The solar storm generated by solar activity can be impact on earth in various area. If solar storm impact on Navaids system, it will be a serious problem for aviation and human safety. The impact analysis of solar strom on Navaids system are performed in three area, ILS, GPS navigation and radio communication for aviation. Analysis result show that Instrument Landing System(LLZ, GP, MB) and Navaids system(VOR, DME, Radar) are not impacted by the solar storm, but GPS system is impacted by solar storm. Also analysis result show that VHF/UHF radio system are not impacted by solar storm, but HF radio system is impacted by solar storm.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.12 no.2
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• pp.83-94
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• 2004

In this overview of RNAV(Area Navigation) covers the general notion of air navigation, the general concept of RNAV and Navigational facilities or elements to achieve RNAV. also, this overview includes RNAV operations on instrument approaches with GPS, VNAV(Vertical Navigation) operations and the future of RNAV.

• International Journal of Aeronautical and Space Sciences
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• v.7 no.1
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• pp.118-128
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• 2006

This paper deals with auto-landing guidance system design applicable to Smart UAV(Unmanned Aerial Vehicle). The proposed guidance law generates horizontal position, velocity and altitude commands in the longitudinal channel and heading angle command in the lateral channel to track a predetermined trajectory for automatic landing. The longitudinal guidance commands are derived from an approximated dynamic equations in vertical plane. These longitudinal guidance commands are appropriately distributed to each control input as the flight mode of Smart UAV is changed. The concept of VOR(VHF Omni-directional Range) guidance system is applied to generate the required heading angle commands to eliminate the lateral deviation from the desired trajectory. The performance of the proposed guidance system for Smart UAV is evaluated using the nonlinear simulation. Simulation results show that the proposed guidance system for auto- landing provides good tracking performance along the predetermined landing trajectory.

• Current Industrial and Technological Trends in Aerospace
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• v.5 no.1
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• pp.93-103
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• 2007

3차원의 공간을 비행하는 항공기의 항행은 조종사가 직접 지상의 지형지물을 참조하며 비행하는 시각비행과 지상의 항행안전시설로부터 무선신호를 받아 비행하는 계기비행으로 구분되어 발전되었다. 현재 계기비행을 수행하기 위한 계기비행절차 수립에 기반이 되는 항행안전무선시설은 기존의 VOR(VHF Omni-directional Range), ILS(Instrument Landing System) 등의 지상기반 항행안전무선시설에서 GNSS (Global Navigation Satellite System)를 이용한 위성기반 항행으로 전환을 목표로 하고 있으며 항행체제 또한 기존의 Fix to Fix 항행체제에서 RNAV(Area Navigation) 체제로 전환되고 있는 추세이다. 계기비행절차는 항공기가 활주로를 이륙하여 항로로 진입하기 위한 계기출발절차(SID), 항로절차(Enroute), 항로에서 목적 공항의 지정된 활주로에 설정된 접근절차(Approach)로 인도하는 도착절차(STAR), 지정된 활주로에 착륙하기 위한 접근절차로 구분될 수 있으며 본문에서는 GNSS를 기반으로 하는 RNAV 절차(RNAVGNSS)에 대한 개괄적인 소개, 설계요건 및 RNAVGNSS 계기비행절차를 성공적으로 이행하기 위한 절차이행모델, RNAVGNSS 절차 수립에 중요하게 고려해야할 사항 등에 대하여 소개하도록 한다.