A Differential Estimation Technique of Troposphere Delay for Precise Positioning in Hydrographic Surveying

To reduce the influence of troposphere delay for precise positioning in hydrographic surveying,a novel estimation method of troposphere delay was proposed based on the differential estimation idea.Taking the value originating from a Saastamoinen model as the priori value,the amended value of the troposphere delay was calculated through precise point positioning.Taking the residual error of the zenith troposphere delay as the unknown parameter,the delay error was determined by Kalman filtering.Then,the troposphere delay of the base station and the marine rover were estimated respectively.These delay values were then entered into the differential estimation model as the initial values,and the precise position of the rover was determined.The result of boat and airplane experiments show that as compared to the conventional kinematic solution,the locattional precision for boats and the airplanes is improved by the differential estimation technique of troposphere delay.Additionally,the precision in the vertical direction increased about 17.6%.