Silvan Hunziker, a PhD student at the Institute for Particle and Astrophysics (IPA) at the ETH Zürich has had his paper on a new PCA algorithm to optimally subtract time- and space-varying backgrounds common on ground-based telescopes in collaboration with Sascha Quanz, Adam Amara (both also of ETH) and Michael Meyer (U. Michigan).  More about the paper can be found at https://arxiv.org/abs/1706.10069.  Below, an example of the several PCA components based on fits to real data.