http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : 전향식 (검색결과 3 건)
-
-
-
지역적인 환경 요인 분석을 통한 GBAS 성능 및 신뢰성 향상에 관한 연구
The International Civil Aviation Organization (ICAO) is developing and verifying Ground-Based Augmentation System (GBAS) for supporting the aircraft precision approach and landing. GBAS, which is a safety-critical system, shall meet a stringent requirement for insuring a hard bound and reliability on the position error. To apprise reliability of the aircraft position error, the GBAS ground facility broadcasts various informations such as B-value and the error standard deviation models to aircraft. The parameters are used to calculate protection level (PL) which estimates the position error of the user aircraft. If the estimated position error doesn't satisfy requirements, the aircraft has to use alternate navigation means. The error of environmental factors makes an evil influence on integrity and availability as well as accuracy. To improve the GBAS performance and reliability, the analysis of environmental factors of local areas is indispensable. For the clear and accurate analysis, the best solution is to collect the GPS real data in the region where GBAS is building and operating. Therefore, this thesis uses the collected GPS real data for a long period of time using the system which is installed and operated in Jeju international airport and at KARI (Korea Aerospace Research Institute) located in Daejeon. This thesis analyzes regional environmental factors, achieves the regional sigma inflation factor and suggests a new GBAS ground facility error standard deviation model with the real data. For ascertaining the environmental effect, the change of ionospheric position error is analyzed according to solar activity and the variation of tropospheric error is assayed based on changes of amount of water vapor. To include the real position error and guarantee of integrity, the sigma inflation factor which is considered the regional environmental conditions is to be determined. Considering the regional environmental factors, the variation of B-value standard deviation due to GPS elevation angle is achieved and a new B-value based GBAS ground facility error standard deviation model is suggested. Comparing with the ICAO model, the standard deviation of the suggested model is proved smaller than the ICAO model at the same elevation angle. To evaluate the suggested model and the achieved sigma inflation factor, using static and dynamic test, the vertical protection level (VPL) is calculated and it is checked whether the VPL is satisfied with the alert limit (AL) of CAT-I, CAT-II, and CAT-III. The results verify that the computed error bounds with inflated sigma are really bounding the possible position error, the VPL meets the AL of CAT-I/II/III and GBAS performance and reliability is improved, using B-value based a new ground facility error standard deviation model and a sigma inflation factor.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
