The Software for Precise Orbit and Clock Combination (SPOCC) is an advanced tool for combining GNSS products for satellite positions and clock corrections. The software relies on official IGS formats and provides weighted averaged results, with weights determined by variance component estimation (VCE). SPOCC first performs the orbit combination, including orbit alignments and outlier filtering, before combining the clock products. In this second step, radial orbit corrections, reference clock adjustments, and inter-system bias alignments are performed before the final combination is carried out.

You can find the software here:  https://gnss.gfz.de/services/spocc 

SPOCC is written in Python, allowing sustainable software maintenance and community-based code extensions. The package’s prototype and main concepts have been developed at GFZ since 2018 and are covered in various publications. Finally, an international developer team has achieved SPOCC’s product readiness and added advanced capabilities. Within the IGS Combination Taskforce, SPOCC is one combination toolbox to test and demonstrate different concepts.