Processing of X-ray Microcalorimeter Data with Pulse Shape Variation   using Principal Component Analysis
  We present a method using principal component analysis (PCA) to process x-ray pulses with severe shape variation where traditional optimal filter methods fail. We demonstrate that PCA is able to noise-filter and extract energy information from x-ray pulses despite their different shapes. We apply this method to a dataset from an x-ray thermal kinetic inductance detector which has severe pulse shape variation arising from position-dependent absorption. 
Daikang Yan, Thomas Cecil, Lisa Gades, Chris Jacobsen, Timothy Madden,   Antonino Miceli
physics.ins-det astro-ph.IM physics.data-an