• Title/Summary/Keyword: Ray-launching method

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Development and performance evaluation of GPS/PL simulator for UAV landing (무인항공기 착륙용 GPS/PL 시뮬레이터 설계 및 성능 평가)

  • Lee, Geon-Woo;Kim, Yong-Hyun;Choi, Jin-Gyu;Park, Chan-Sik;Lee, Sang-Jeong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.36 no.1
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    • pp.39-47
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    • 2008
  • Automatic landing performance of UAV can be enhanced by adding Pseudolite(PL) to GPS. However, it is very hard to install and operate PL with confidence because GPS satellites are moving and the landing zone are usually changeable. The coverage and accuracy of combined GPS and PL can be estimated by using simulator and the correct information is very crucial to UAV operation. In this paper, design, implementation and evaluation of GPS/PL simulator for UAV landing are given. A very realistic coverage estimation is obtained using GIS data and ray launching method with considerations of the transmitter power level, altitude of UAV, number and location of PL. The expected accuracy is estimated using DOP and NSP computed using both GPS and PL. The performance of simulator is evaluated by comparing with the results of a real GPS receiver, and the certified simulator shows the required accuracy for UAV landing can be easily met by proper installation of at least 2 PLs.

A Study on the Profiling System in the Aviation Security (항공보안에서의 프로파일링 연구)

  • Hwang, Ho-Won;Lee, Kyu-Hang
    • The Korean Journal of Air & Space Law and Policy
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    • v.22 no.2
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    • pp.155-175
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    • 2007
  • As intellectual terror threats increase, we feel the limit in coping with those threats and the things we do are placing traditional X-ray machines & ETD and increasing aviation security staffs. In fact, even if air transportation system is the fast and most efficient transportation methods, it is true that there are many inconveniences to endure due to terror threats. In the name of security, even if we make a lot of efforts and time to screen both good-natured passengers, baggage, cargo and suspicious passengers, it is impossible to screen perfectly and it is not an efficient methods. Therefore, we introduce profiling system that reduce the effort to screen good-natured passengers but focus on screening dangerous passengers and baggages. Profiling system strengthens aviation security, using the concept "Selection & Concentration". Israel started to introduce manual profiling system in aviation security, which is interviewing suspicious passengers and it has been used in crime investigation since 1960. And it has been upgraded and diversified to CAPPS(Computer Assisted Passenger Screening Program) and SPOT(Screening Passenger by Observation). So, this theses is to study on the concept & kind of profiling and profiling methods adopted in airlines. Also it presents the method of introduction of profiling system in Korea and the necessity of making law on it.

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