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An Analysis of GPS Station Positioning Accuracy Variations According to Locations of Obstacles

장애물 위치에 따른 GPS 기준국 측위정확도 변화분석

  • Sohn, Dong-Hyo (Graduate school of Inha University) ;
  • Park, Kwan-Dong (Department of Geoinformatic Engineering, Inha University) ;
  • Jung, Wan-Suk (Department of technical development research, Spatial Information Research Institute) ;
  • Kee, Changdon (School of Mechanical and Aerospace Engineering, Seoul National University)
  • 손동효 (인하대학교 대학원) ;
  • 박관동 (인하대학교 지리정보공학과) ;
  • 정완석 (대한지적공사 공간정보연구원) ;
  • 기창돈 (서울대학교 기계항공공학부)
  • Received : 2013.07.29
  • Accepted : 2013.10.08
  • Published : 2013.10.31

Abstract

This paper focuses on GPS positioning accuracy variations according to locations of obstacles which surround GPS station. We derived precise coordinates of a GPS station which has a good visibility. Its observation data was rewritten by assuming signal blocking due to obstacle in the elevation angle of $10^{\circ}$ to $70^{\circ}$. We processed daily and hourly data for 10 days. In the results using daily data, RMSE was at 10mm level. And RMSE increased to 100mm levels in case of hourly data. As the elevation angle of obstacle increased, the horizontal and vertical RMSE increased, while the height estimates decreased. These results showed the higher the elevation angle of the obstacle increased the loss of large amounts of data by blocking satellite signals direction. In terms of the direction, when the blocking thing was located in the east or west, the coordinate has larger error in the east-west direction. And if signal was blocked at the south direction, the difference between the east-west error and the south-north position error was reduced.

이 연구에서는 GPS 기준국 주변에 존재하는 장애물의 방향과 고도각이 좌표 정확도 변화에 미치는 영향을 시뮬레이션을 통해 분석하고자 한다. 최적의 관측환경에 있는 기준국의 정밀좌표를 산출한 뒤 고도각 $10^{\circ}$부터 $70^{\circ}$까지의 장애물이 동, 서, 남 방향에 각각 존재한다고 가정하고 관측자료를 재구성하였다. 10일간의 관측자료를 이용하여 일단위와 시간단위로 각각 처리하였다. 일단위 처리결과에서는 RMSE가 10mm 내외였으나 시간단위 결과에서는 100mm 수준까지 증가하였다. 장애물의 고도각이 높아질수록 수평 및 수직방향 RMSE는 증가하였고 높이 추정값은 감소하였다. 방향에 따른 분석에서는 동쪽이나 서쪽에 장애물이 존재할 때 남북방향에 비해 동서방향으로 위치오차가 더 크게 증가하였고 남쪽 장애물인 경우에는 동서방향의 오차폭이 상대적으로 작게 나타났다.

Keywords

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Cited by

  1. Positioning Accuracy Analysis According to the Change of Blockage Location and GNSS Signal Combination vol.22, pp.3, 2014, https://doi.org/10.7319/kogsis.2014.22.3.039