Modeling method and device for zenith tropospheric delay as well as measuring method and device

Abstract

The invention provides a modeling method for zenith tropospheric delay. The modeling method comprises the following steps: S11, obtaining a zenith tropospheric delay amount actually measured in each observation station; S12, calculating an annular mean value ZTDh of the zenith tropospheric delay amount corresponding to the observation station, fitting based on ZTDh to obtain an elevation correction coefficient beta and an annular mean delay amount ZTD0 naturalized to an ellipsoidal surface, corresponding to the observation station, and obtaining a single-day delay amount ZTD0(doy) after elevation correction, corresponding to the observation station according to the beta; S13, fitting based on ZTD0(doy) to obtain a period constant term A0, amplitude and initial phases A1 and d1 of an annual periodic term as well as amplitude and initial phases A2 and d2 of a semi-annual periodic term, corresponding to the observation station; S14, building a latitude and longitude grid function model based on the Chinese mainland area, and calculating based on the parameters A0, A1, d1, A2 and d2 corresponding to the observation station to obtain A0, A1, d1, A2 and d2 corresponding to each grid point in the grid function model. The modeling method is suitable for the Chinese mainland area, the precision is remarkably improved, and the overall service level of a satellite navigation positioning system of the Chinese mainland area can be improved.

Description

technical field [0001] The invention relates to the technical field of satellite positioning, in particular to a zenith tropospheric delay modeling method and device, and a measurement method and device. Background technique [0002] Global Navigation Satellite System (GNSS) refers to a system that uses electromagnetic waves emitted by navigation satellites to locate, navigate and time objects on the earth. The height of GNSS satellites is 20,000 to 40,000 kilometers. Users receive electromagnetic waves emitted by them, and perform positioning through code measurement values ​​and carrier phase observation values. When the signal transmitted by the GNSS satellite passes through the atmosphere, the speed will change, and the propagation path will also bend, which is called the atmospheric delay error. In GNSS measurement and positioning, generally only the change of signal propagation velocity is considered, because the curvature of the propagation path is relatively small a...

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Problems solved by technology

(3) VMF1 (Vienna Mapping Function 1) and UNBvmf models, which are calculated according to the numerical weather model (Numerical Weather Model, NWM), provide global grid data with a sampling rate of 6 hours, and the accuracy is about 2cm. The disadvantages of these two models is the need to download their product in real time

[0005] Although the existing empirical model of tropospheric zenith delay can well correct the tropospheric zenith delay in the process of GNSS navigation and positioning, it still has the following shortcomings: (1) The tropospheric zenith delay calculated based on meteorological data Delay modeling does not make full use of the zenith delay data calculated by GNSS; (2) the existing models generally use spherical harmonic functions or atmospheric parameter tables divided by latitude, which are not suitable for small areas. Only the VMF1 model uses grid function, but the use of the VMF1 function is too complicated; (3) the existing model does not have a corrected model for the tropospheric zenith delay in mainland China

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