The Wuhan Combination Center (WCC) was formally approved by the IGS Governing Board (GB) in 2024. It aims at providing combined high-precision and highly-reliable multi-GNSS satellite products. The priorities of the WCC include: (1) The WCC serves as a backup combination institution; (2) The WCC incorporates the MGEX or demonstration products into the combination; (3) The WCC combined products contain all-frequency code/phase biases to avoid day-boundary discontinuity.

The tasks of the WCC are:

(1) The WCC will focus on combining orbit, clock, and code/phase bias products, covering ultra-rapid, rapid, and final product lines;

(2) Combined products for GPS, GLONASS, and Galileo will be released initially and BDS/QZSS will be introduced later;

(3) PPP-AR(Precise Point Positioning with Ambiguity Resolution) validation will be carried out to monitor the quality and reliability of combined products. The WCC will enhance the consistency, interoperability, and reliability of AC-specific GNSS products, addressing the challenges in areas such as time and frequency transfer, geodesy, and satellite positioning.

Work Objectives:

(1)Achieve stable combination of full-frequency GPS, GLONASS, Galileo, and BDS/QZSS orbit, clock, and bias products.

(2)Ensure a minimum availability rate of 95% for ultra-rapid and rapid combined products, and over 99% for final combined products.

(3)Conduct cross-validation between GNSS OPS and MGEX products.

(4)Incorporate carrier-phase bias products into the combination process to enable PPP-AR .

(5)Maintain continuity of the combined products across day boundaries to provide more stable services for time and frequency transfer applications.

(6)Distribute the combined products to the GNSS user community to support geodetic, geophysical, and time–frequency applications.