  We present progress results from the FASTSUM collaboration's programme to
determine the spectrum of the bottomonium system as a function of temperature
using a variety of approaches. In this contribution, the Backus Gilbert method
is used to reconstruct spectral functions from NRQCD meson correlator data from
FASTSUM's anisotropic ensembles at nonzero temperature. We focus in particular
on the resolving power of the method, providing a demonstration of how the
underlying resolution functions can be probed by exploiting the Laplacian
nature of the NRQCD kernel. We conclude with estimates of the bottomonium
ground state mass and widths at nonzero temperature.
