High-precision light curves of geostationary objects: The PHANTOM ECHOES 2 RPO campaign

We present results from an extensive optical observation campaign that monitored the Geostationary satellites Intelsat 10–02, Mission Extension Vehicle 2, Thor 5, Thor 6, Thor 7, and Meteosat 11 over a 14 week period that covered the proximity operations and docking of Mission Extension Vehicle 2 with Intelsat 10–02. High-cadence single-color photometric observations are supplemented with targeted multi-color observations, high resolution imaging, and passive radio frequency positioning obtained using complementary facilities.

The photometric signatures of the six targets are presented in the form of two-dimensional color maps. A selection of interesting features are investigated in further detail, including a rapid glinting behavior in Thor 6; a brightening event from Meteosat 11; using glints to constrain the unresolved positions of Intelsat 10–02 and MEV-2; changes in the photometric signature of Intelsat 10–02 before and after docking; and signatures of attitude changes and maneuvering in the light curves of MEV-2.

A detailed description of the photometric data reduction pipeline is also presented, with a focus on details that must be considered when aiming for sub-percent photometric precision.