On December 16, 2025 (Beijing Time), the IGS Task Force for the format standard of the combination statistics held its online Kick-off Meeting. Chaired by Prof. Jianghui Geng, the meeting aimed to establish the strategic direction and planning for the new generation of combination statistical standard formats. The discussion focused on four key technical topics: 1) the logical basis for the primary classification index (Analysis Center name vs. product type); 2) selection of the combination standard format; 3) the necessity of including multi-frequency signal biases in the statistical scope; and 4) the feasibility of integrating ERP combination information.

It was noted that the traditional combination files separate orbit and clock information, failing to meet the demands of Analysis Centers for refined quality monitoring and the requirements of PPP users for high-precision and high-reliability positioning. Consequently, the meeting established three core goals for the new standard: 1) facilitating Analysis Centers in troubleshooting product issues; 2) assisting PPP users in excluding outliers in orbits, clocks, and biases; and 3) developing auxiliary tools for plotting combination statistics. Furthermore, the meeting outlined the architecture of the new format, which will encompass: metadata (antenna models, combination strategies, reference frequencies, sampling rates, etc.), orbit statistics (Helmert transformation parameters, radial/along-track/cross-track errors, system time, etc.), as well as clock statistics (weights, excluded epochs, offsets, RMSE, etc.) and bias statistics. Following in-depth discussions, the meeting decided to integrate ERP combination information and consider the inclusion of coordinate combination content. Ultimately, "product type" was established as the primary classification logic, and three formats—SINEX, JSON, and YAML—were selected for subsequent testing and evaluation.

Representatives from various IGS Analysis Centers, as well as experts and scholars in the field of precision positioning from around the globe, attended the Kick-off Meeting. Through this meeting, the Task Force further consolidated technical consensus on the new generation of combination statistical formats and defined the implementation path, laying a solid foundation for modernizing IGS data standards and supporting high-precision GNSS applications.