The IAU Centre for the Protection of the Dark and Quiet Sky from Satellite Constellation Interference (CPS), established in early 2022 and co-hosted by NSF’s NOIRLab and the SKA Observatory, was created to unify efforts to mitigate the effects of satellite constellations on astronomy. SatHub, one of the four sub-groups of CPS, focuses on software and related tools to aid observers and industry partners in addressing some of the issues caused by commercial satellite constellations.

Currently, SatHub software efforts are concentrated in two main areas: SatChecker, a satellite ephemeris prediction service which is nearing a beta phase, and a satellite brightness observation database, still in early development.

One of the primary tools needed to mitigate the effects of commercial satellite constellations is a robust ephemeris service that can provide accurate satellite positions as well as estimated brightness. This can reduce or remove the need to recreate satellite interference predictions across multiple observatory locations. The SatChecker service will be available via API and web interfaces with the ability to provide satellite passage information for specific pointing/FOV/exposure times, as well as general ephemeris information for specific satellites. SatChecker will also utilize multiple data sources providing orbital data in both two-line element (TLE) and orbital ephemeris message (OEM) formats to both predict future passes and provide archival information. Additionally, SatChecker could also be used to conduct simulations of how satellite constellations can impact specific science cases, such as Rubin Observatory’s LSST and associated follow-up observations.

Another focus of SatHub’s development efforts is a data repository to collect satellite brightness observations - visual, optical, and the images themselves. Currently work has begun on an image upload website (Trailblazer), but we will be working on developing a repository to collect all brightness observation measurements and make them easily accessible for review or download. One of the main focus points is creating a standardized data format for all relevant brightness information, and ensuring that there is a consistent way to process images from different sources. This information can also be used by satellite operators to quantify the effects of any mitigations they do to reduce satellite brightness.