HUTG: a next-generation IGS real‑time combined GIM via two‑step global and regional correction with robust weighting from HENU and UPC‑IonSAT

Kualong Xu; Qi Liu; Manuel Hernández-Pajares; Enric Monte-Moreno; Heng Yang; Germán Olivares-Pulido; David Roma-Dollase; Alberto García-Rigo; Ningbo Wang; Zishen Li; Ang Liu; Clément Ubelmann; Nicolas Lelarge; Qile Zhao; Qiang Zhang; Andrzej Krankowski; Xingliang Huo; Adam Fron; Axel Rülke; Andrea Stürze; Loukis Agrotis; Reza Ghoddousi-Fard; Chuanding Zhang; Li Yang