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Application of the Difference Method in a Fault Test on GPS Carrier Phase Measurements

차분 기법을 적용한 GPS 반송파 위상 측정치 고장 검사

  • Son, Eunseong (Satellite Navigation Team, Korea Aerospace Research Institute) ;
  • Im, Sung-Hyuck (Satellite Navigation Team, Korea Aerospace Research Institute) ;
  • Kim, Koon-Tack (SBAS System Engineering & Integration Team, Korea Aerospace Research Institute)
  • 손은성 (한국항공우주연구원 위성항법팀) ;
  • 임성혁 (한국항공우주연구원 위성항법팀) ;
  • 김군택 (한국항공우주연구원 체계종합팀)
  • Received : 2017.10.16
  • Accepted : 2017.11.27
  • Published : 2017.12.31

Abstract

This study performed fault test on global positoining system (GPS) carrier phase measurements, which is a preprocessing step to generate the positioning correction information based on the global navigation satellite system (GNSS) infrastructure. The existing carrier acceleration ramp step test (CARST) method affects the test result by using the mean value to eliminate the receiver clock error. In this regard, this study applied differencing and compared its results with those of the existing CARST. The fault simulation that applied artificial faults to the actual data found that the fault could be detected independently on each satellite when difference method was applied, and the single difference CARST and the double difference CARST produced similar results. The comparison with the existing method using actual data demonstrated the strengths and weaknesses of satellite and station single difference. Nevertheless, it is our understanding that it would require an additional analysis to determine whether the results were affected by the satellite or receiver clock error.

이 연구에서는 GNSS (global navigation satellite system) 인프라 기반 측위 보정정보 생성을 위한 전처리 단계인 GPS (global positioning system) 반송파 위상 측정치의 고장 검사를 수행하였다. 기존 CARST (carrier acceleration ramp step test) 방법은 수신기 시계 오차를 제거하기 위해 평균값을 이용함으로써 검사 대상에 영향을 준다. 따라서 이 연구에서는 차분 기법을 적용하여 기존 CARST 결과와 비교하였다. 실 데이터에 인위적인 고장을 인가하여 고장 시뮬레이션을 수행한 결과 차분 기법을 적용할 경우 각각의 위성에 대해 독립적인 고장 검출이 가능한 것으로 판단되었으며 단일차분과 이중차분은 유사한 결과를 나타내었다. 실 데이터를 이용하여 기존의 방법과 비교한 결과 위성 간 차분, 수신국간 차분 결과의 장단점을 확인할 수 있었다. 그러나 결과 값에 대한 위성 및 수신기 시계 오차의 영향은 추가적인 분석이 필요할 것으로 판단된다.

Keywords

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