CHINA THREE GORGES CORPORATION

A method, apparatus, and system are disclosed for network-wide fixing of widelane ambiguities based on ionospheric correlation. The method involves: dividing a continuous operational reference system (CORS) network into ambiguity calculation units; collecting four or more groups of fixed widelane ambiguities within these units; constructing a regional ionospheric delay model; and judging false fixes against this model. If fewer than four groups of remaining widelane ambiguity data exist, the process exits. Alternative widelane ambiguity values and corresponding widelane ionospheric delays are then calculated. Finally, it's determined if these alternative values meet a judgment condition. Ionospheric delays corresponding to unfixed widelane ambiguities are interpolated via spatial correlation, using fixed widelane ambiguities within the CORS region. This enables fixing remaining unfixed widelane ambiguities using larger wavelength widelane observed values and verifies correctly fixed widelane ambiguities.

The provided is a modeling method of tropospheric delay for arid-areas including sandy, gobi and desert regions based on GNSS. The modeling method incudes: obtaining a troposphere zenith hydrostatic delay ZHD and a troposphere zenith wet delay ZWD by utilizing a GPT-3 model, and summing to obtain a troposphere zenith total delay ZTD; inversely calculating the ZTD by utilizing a ground-based GNSS, obtaining a high-precision ZWD inversed by the GNSS by calculating a difference between the ZTD and the troposphere zenith hydrostatic delay ZHD obtained by a Saastamonien model, inversely calculating an atmospheric weighted average temperature T′ m by utilizing an ERA5 data set, performing linear correction to obtain a corrected temperature T m r , and calculating a priori value ZWD 0 of the high-precision ZWD; and correcting the ZWD 0 , and adding the corrected ZWD 0 with the ZHD to obtain a corrected value of the high-precision ZTD.

The provided is a modeling method of tropospheric delay for arid-areas including sandy, gobi and desert regions based on GNSS. The modeling method incudes: obtaining a troposphere zenith hydrostatic delay ZHD and a troposphere zenith wet delay ZWD by utilizing a GPT-3 model, and summing to obtain a troposphere zenith total delay ZTD; inversely calculating the ZTD by utilizing a ground-based GNSS, obtaining a high-precision ZWD inversed by the GNSS by calculating a difference between the ZTD and the troposphere zenith hydrostatic delay ZHD obtained by a Saastamonien model, inversely calculating an atmospheric weighted average temperature T′ m by utilizing an ERA5 data set, performing linear correction to obtain a corrected temperature T m r , and calculating a priori value ZWD 0 of the high-precision ZWD; and correcting the ZWD 0 , and adding the corrected ZWD 0 with the ZHD to obtain a corrected value of the high-precision ZTD.