TY - JOUR

T1 - Improving VLBI analysis by tropospheric ties in GNSS and VLBI integrated processing

AU - Wang, Jungang

AU - Ge, Maorong

AU - Glaser, Susanne

AU - Balidakis, Kyriakos

AU - Heinkelmann, Robert

AU - Schuh, Harald

N1 - Funding information: We thank the IGS and IVS for providing the GNSS and VLBI observations, the GNSS satellite orbits and clocks, Vienna University of Technology for the tropospheric product. Jungang Wang is financially supported by the Helmholtz ? OCPC Postdoc Program (grant no. ZD202121). Kyriakos Balidakis is funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) ? Project-ID 434617780 ? SFB 1464 (TerraQ). The authors would like to thank the editor J?rgen Kusche, the associate editor Zinovy M. Malkin, and three anonymous referees who kindly reviewed this manuscript and provided valuable suggestions and comments. We thank the IGS and IVS for providing the GNSS and VLBI observations, the GNSS satellite orbits and clocks, Vienna University of Technology for the tropospheric product. Jungang Wang is financially supported by the Helmholtz – OCPC Postdoc Program (grant no. ZD202121). Kyriakos Balidakis is funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – Project-ID 434617780 – SFB 1464 (TerraQ). The authors would like to thank the editor Jürgen Kusche, the associate editor Zinovy M. Malkin, and three anonymous referees who kindly reviewed this manuscript and provided valuable suggestions and comments.

PY - 2022/4/26

Y1 - 2022/4/26

N2 - Tropospheric delay modeling is challenging in high-precision Very Long Baseline Interferometry (VLBI) analysis due to the rapid water vapor variation and imperfect observation geometry, where observations from Global Navigation Satellite Systems (GNSS) co-locations can enhance the VLBI analysis. We investigate the impact of tropospheric ties in the VLBI and GNSS integrated processing during the CONT05–CONT17 campaigns, and present a method that automatically handles the systematic tropospheric tie biases. Applying tropospheric ties at VLBI–GNSS co-locations enhances the observation geometry and improves the solution reliability. The VLBI network is stabilized, with station coordinate repeatability improved by 12% horizontally and by 28% vertically, and the network scale improved by 32%. The Earth Orientation Parameters (EOP) improve by up to 20%. Both zenith delay and gradient ties contribute to the improvement of EOP, whereas the gradient ties contribute mainly to the improvement of length of day and celestial pole offsets.

AB - Tropospheric delay modeling is challenging in high-precision Very Long Baseline Interferometry (VLBI) analysis due to the rapid water vapor variation and imperfect observation geometry, where observations from Global Navigation Satellite Systems (GNSS) co-locations can enhance the VLBI analysis. We investigate the impact of tropospheric ties in the VLBI and GNSS integrated processing during the CONT05–CONT17 campaigns, and present a method that automatically handles the systematic tropospheric tie biases. Applying tropospheric ties at VLBI–GNSS co-locations enhances the observation geometry and improves the solution reliability. The VLBI network is stabilized, with station coordinate repeatability improved by 12% horizontally and by 28% vertically, and the network scale improved by 32%. The Earth Orientation Parameters (EOP) improve by up to 20%. Both zenith delay and gradient ties contribute to the improvement of EOP, whereas the gradient ties contribute mainly to the improvement of length of day and celestial pole offsets.

KW - GNSS

KW - VLBI

KW - Combination on the observation level

KW - Tropospheric tie

KW - Earth orientation parameters

UR - http://www.scopus.com/inward/record.url?scp=85128980130&partnerID=8YFLogxK

U2 - 10.1007/s00190-022-01615-y

DO - 10.1007/s00190-022-01615-y

M3 - Article

VL - 96

JO - Journal of geodesy

JF - Journal of geodesy

SN - 0949-7714

IS - 4

M1 - 32

ER -