It is an attractive method to combine GPS observations with the information from other surveying system to improve the ambiguity resolution. This research is conducted to investigate how to obtain the prior height inf...It is an attractive method to combine GPS observations with the information from other surveying system to improve the ambiguity resolution. This research is conducted to investigate how to obtain the prior height information in bathymetric surveying by GPS positioning and how to use the prior height information and to obtain a robust result. The authors deal with the collection and the description of the prior height and the method using height validation to improve the ambiguity resolution. The principle of the method, the relationships between the height threshold and the ambiguity search space are presented. A method to determine the threshold for the height validation is suggested. The field tests are carried out to show the feasibility of the proposed methods.展开更多
Navigation system integrity monitoring is crucial for mission(e.g.safety)critical applications.Receiver autonomous integrity monitoring(RAIM)based on consistency checking of redundant measurements is widely used for m...Navigation system integrity monitoring is crucial for mission(e.g.safety)critical applications.Receiver autonomous integrity monitoring(RAIM)based on consistency checking of redundant measurements is widely used for many applications.However,there are many challenges to the use of RAIM associated with multiple constellations and applications with very stringent requirements.This paper discusses two positioning techniques and corresponding integrity monitoring methods.The first is the use of single frequency pseudorange-based dual constellations.It employs a new cross constellation single difference scheme to benefit from the similarities while addressing the differences between the constellations.The second technique uses dual frequency carrier phase measurements from GLONASS and the global positioning system for precise point positioning.The results show significant improvements both in positioning accuracy and integrity monitoring as a result of the use of two constellations.The dual constellation positioning and integrity monitoring algorithms have the potential to be extended to multiple constellations.展开更多
文摘It is an attractive method to combine GPS observations with the information from other surveying system to improve the ambiguity resolution. This research is conducted to investigate how to obtain the prior height information in bathymetric surveying by GPS positioning and how to use the prior height information and to obtain a robust result. The authors deal with the collection and the description of the prior height and the method using height validation to improve the ambiguity resolution. The principle of the method, the relationships between the height threshold and the ambiguity search space are presented. A method to determine the threshold for the height validation is suggested. The field tests are carried out to show the feasibility of the proposed methods.
文摘Navigation system integrity monitoring is crucial for mission(e.g.safety)critical applications.Receiver autonomous integrity monitoring(RAIM)based on consistency checking of redundant measurements is widely used for many applications.However,there are many challenges to the use of RAIM associated with multiple constellations and applications with very stringent requirements.This paper discusses two positioning techniques and corresponding integrity monitoring methods.The first is the use of single frequency pseudorange-based dual constellations.It employs a new cross constellation single difference scheme to benefit from the similarities while addressing the differences between the constellations.The second technique uses dual frequency carrier phase measurements from GLONASS and the global positioning system for precise point positioning.The results show significant improvements both in positioning accuracy and integrity monitoring as a result of the use of two constellations.The dual constellation positioning and integrity monitoring algorithms have the potential to be extended to multiple constellations.
