In this paper, Matsuo et al. (arxiv link) propose a method for planet detection and characterization with LIFE, named “phase-space synthesis decomposition” (PSSD). PSSD focuses on the correlation of the planetary signal over the entire wavelength range instead of that along the baseline rotation, leading to the relaxation of the technical requirements on the signal stability. Through the numerical simulations, they confirmed that multiple terrestrial planets in the habitable zone around a Sun-like star at 10 pc can be detected and characterized despite high levels and long durations of systematic noise. PSSD is also more robust against a sparse sampling of the array rotation compared to purely rotation-based signal extraction. The LIFE team  hopes that this study is the starting point for a discussion on how to relax the technical requirements of LIFE from a perspective of data reduction.

Image and spectrum reconstruction under photon-noise limited condition.

(a) Reconstructed two-dimensional image. The white arrows denote positions of Earth, Mars and Venus, respectively.

Panel (b) shows the noise floors for systematic OPD RMS errors of 3.8 (black), 7.5 (yellow), and 11.3 nm (brown) were compared with the planet signals (star symbol). The noise floor for each OPD error was calculated for a reconstructed two dimensional image without the planet signals. The gray line shows the noise floor for the ideal case (i.e., only the shot noise) as a reference

(c) Reconstructed spectra of the three planets. The grey line and grey vertical bar of each panel show the input model and the standard deviation of each data point derived through 100 numerical simulations,
respectively