Department News
GPS Network-Based Approach to Mitigate Residual Tr
Seminar Date
2005-03-30
Author
빈종훈
Date
2005-03-30
Views
1966
세미나 날짜 : 2005/03/30
1. 제 목 : GPS Network-Based Approach to Mitigate Residual Tropospheric Delay In Low Latitude Area
2. 연 사 : Dr. Samsung Lim (School of Surveying and Spatial Information Systems
The University of New South Wales, Sydney NSW 2052, Australia)
3. 일 시 : 2005년 3월 30일 (Wednesday) 11:00 – 11:50AM
4. 장 소 : 301동 1512호
5. 내 용 :
The performance of existing a priori or physical models has been unsatisfactory when mitigating the tropospheric delay of the GPS measurements. A strong spatio-temporal variation of the wet component in the troposphere leaves us in a peculiar predicament. The residual tropospheric delay will remain in the measurements and affect the estimation of related parameters. In an area of hot and wet climate conditions, especially in the equatorial or low latitude region, the strong troposphere effect on GPS measurements is unquestionable. High accuracy GPS positioning requires the residuals to be reduced by an appropriate modeling. A common approach is to apply the estimation of troposphere scale factor or to use a stochastic estimation, e.g., a first-order Gauss-Markov or random walk process. Over the past few years the concept of network-based positioning has been extensively developed in order to better model the distance-dependent errors such as the ionospheric delay and orbit biases as well as the tropospheric delay. As a result, static and kinematic GPS positioning can be undertaken for longer baselines than the "traditional" single-base station techniques. The GPS CORS network in the region of low latitude gives us an opportunity to utilize networked modeling of the residual tropospheric delay. This approach is known as pure geometric modeling and takes advantage of the measurements from the existing GPS CORS network. A study area in South-East Asia is selected, which covers Malaysia and Singapore. This study is concentrated on two monsoon seasons; North-East monsoon (November to early March) and the South-West monsoon (early May to August), both are responsible for heavy rainfall. Previous study results in this area show that the tropospheric effect significantly impacts on high accuracy positioning. The proposed geometric modeling can mitigate the residual tropospheric delay even during the two monsoons. A test of the modeling includes post-processing of the network data in a kinematic mode and is evaluated by the number of ambiguities resolved and the precision of the coordinate results.
6. 약 력 :
2004.7 - Present Senior Lecturer, School of Surveying & SIS, UNSW, Australia
1997.3 - 2004.9 Associate Professor, Dept. of Geoinformatics, Inha University
2002.3 - 2004.1 Vice Director, Computing and Information Center, Inha University
1996.1 - 1997.2 Senior Researcher, Renault-Samsung Motors
1995.12 Ph.D., Dept. of Aerospace Engineering, The University of Texas at Austin, USA
1990.2 M.A., Dept. of Mathematics, Seoul National University
1988.2 B.A., Dept. of Mathematics, Seoul National University
7. 문 의 : 기계항공공학부 기창돈 교수 (☏ 880-1912)
관련글 : 없음
1. 제 목 : GPS Network-Based Approach to Mitigate Residual Tropospheric Delay In Low Latitude Area
2. 연 사 : Dr. Samsung Lim (School of Surveying and Spatial Information Systems
The University of New South Wales, Sydney NSW 2052, Australia)
3. 일 시 : 2005년 3월 30일 (Wednesday) 11:00 – 11:50AM
4. 장 소 : 301동 1512호
5. 내 용 :
The performance of existing a priori or physical models has been unsatisfactory when mitigating the tropospheric delay of the GPS measurements. A strong spatio-temporal variation of the wet component in the troposphere leaves us in a peculiar predicament. The residual tropospheric delay will remain in the measurements and affect the estimation of related parameters. In an area of hot and wet climate conditions, especially in the equatorial or low latitude region, the strong troposphere effect on GPS measurements is unquestionable. High accuracy GPS positioning requires the residuals to be reduced by an appropriate modeling. A common approach is to apply the estimation of troposphere scale factor or to use a stochastic estimation, e.g., a first-order Gauss-Markov or random walk process. Over the past few years the concept of network-based positioning has been extensively developed in order to better model the distance-dependent errors such as the ionospheric delay and orbit biases as well as the tropospheric delay. As a result, static and kinematic GPS positioning can be undertaken for longer baselines than the "traditional" single-base station techniques. The GPS CORS network in the region of low latitude gives us an opportunity to utilize networked modeling of the residual tropospheric delay. This approach is known as pure geometric modeling and takes advantage of the measurements from the existing GPS CORS network. A study area in South-East Asia is selected, which covers Malaysia and Singapore. This study is concentrated on two monsoon seasons; North-East monsoon (November to early March) and the South-West monsoon (early May to August), both are responsible for heavy rainfall. Previous study results in this area show that the tropospheric effect significantly impacts on high accuracy positioning. The proposed geometric modeling can mitigate the residual tropospheric delay even during the two monsoons. A test of the modeling includes post-processing of the network data in a kinematic mode and is evaluated by the number of ambiguities resolved and the precision of the coordinate results.
6. 약 력 :
2004.7 - Present Senior Lecturer, School of Surveying & SIS, UNSW, Australia
1997.3 - 2004.9 Associate Professor, Dept. of Geoinformatics, Inha University
2002.3 - 2004.1 Vice Director, Computing and Information Center, Inha University
1996.1 - 1997.2 Senior Researcher, Renault-Samsung Motors
1995.12 Ph.D., Dept. of Aerospace Engineering, The University of Texas at Austin, USA
1990.2 M.A., Dept. of Mathematics, Seoul National University
1988.2 B.A., Dept. of Mathematics, Seoul National University
7. 문 의 : 기계항공공학부 기창돈 교수 (☏ 880-1912)
관련글 : 없음
