Influence of mapping function parameters on global GPS network analyses: Comparisons between NMF and IMF

摘要: [1] One major part in the error budget of GPS measurements is imperfect modeling tropospheric delay. By processing a global network 195 stations we have compared two different mapping techniques: (1) commonly used Niell hydrostatic function (NMF) and (2) isobaric (IMF) based on numerical weather fields. The solutions reveal significant differences derived zenith total delay (ZTD) parameters site positions. largest occur Antarctica, where annual mean heights differ by up to 15 mm. We infer that are related model deficiencies NMF since a) IMF improves repeatability station high southern latitudes significantly, b) using reduces dependence solution elevation cut-off angle about 20%. In conclusion, use (MF) meteorological data strongly recommended for analyses.