With the rapid development of multi-frequency Global Navigation Satellite Systems(GNSS),Geometry-Free(GF)Three-Carrier Ambiguity Resolution(TCAR)has become an increasingly viable solution for high-precision positionin...With the rapid development of multi-frequency Global Navigation Satellite Systems(GNSS),Geometry-Free(GF)Three-Carrier Ambiguity Resolution(TCAR)has become an increasingly viable solution for high-precision positioning.The GF TCAR model enables satellite-by-satellite ambiguity resolution,offering robustness independent of satellite geometry.However,its performance in network Real-Time Kinematic(RTK)applications is highly sensitive to residual atmospheric errors.To accurately quantify these impacts and optimize ambiguity resolution strategies,this study proposes an enhanced analysis framework and presents a comprehensive sensitivity analysis of the GF TCAR model under different atmospheric and noise conditions.Theoretical derivations and simulations confirm that non-dis persive errors,such as tropospheric delays,are effectively mitigated within the GF framework.In addition,the study establishes quantitative accuracy thresholds for ionospheric modeling across constellations.While Extra-Wide-Lane(EWL)and Wide-Lane(WL)ambiguities remain robust against ionospheric errors of up to dozens of Total Electron Content Units(TECU)and several TECU,respectively,Narrow-Lane(NL)ambiguity resolution is the most challenging step,requiring residual errors to remain about within±0.2 TECU.Furthermore,the analysis shows that EWL ambi guity resolution is relatively insensitive to measurement noise,whereas WL ambiguity resolution is predominantly noise-limited,especially as the EWL wavelength increases.These findings provide valuable error-tolerance references for the quality control of ionospheric corrections in network RTK services.展开更多
基金National Natural Science Foundation of China(Grant No.42561160140,42404052)GHP/033/22SZ Guangdong-Hong Kong Technology Cooperation Funding Scheme(Shenzhen Science and Technology Program under Grant SGDX20230116092503007)+2 种基金the SpecialProject for Universities Directly Under the Ministry to Serve Jiangsu’s High-Quality Developmentthe Hong Kong General Research Fund(Grant No.15229622)the University Grants Committee of Hong Kong under the General Research Fund 1060(GRF)(Grant No.15212525).
摘要With the rapid development of multi-frequency Global Navigation Satellite Systems(GNSS),Geometry-Free(GF)Three-Carrier Ambiguity Resolution(TCAR)has become an increasingly viable solution for high-precision positioning.The GF TCAR model enables satellite-by-satellite ambiguity resolution,offering robustness independent of satellite geometry.However,its performance in network Real-Time Kinematic(RTK)applications is highly sensitive to residual atmospheric errors.To accurately quantify these impacts and optimize ambiguity resolution strategies,this study proposes an enhanced analysis framework and presents a comprehensive sensitivity analysis of the GF TCAR model under different atmospheric and noise conditions.Theoretical derivations and simulations confirm that non-dis persive errors,such as tropospheric delays,are effectively mitigated within the GF framework.In addition,the study establishes quantitative accuracy thresholds for ionospheric modeling across constellations.While Extra-Wide-Lane(EWL)and Wide-Lane(WL)ambiguities remain robust against ionospheric errors of up to dozens of Total Electron Content Units(TECU)and several TECU,respectively,Narrow-Lane(NL)ambiguity resolution is the most challenging step,requiring residual errors to remain about within±0.2 TECU.Furthermore,the analysis shows that EWL ambi guity resolution is relatively insensitive to measurement noise,whereas WL ambiguity resolution is predominantly noise-limited,especially as the EWL wavelength increases.These findings provide valuable error-tolerance references for the quality control of ionospheric corrections in network RTK services.