From DeepCore to PINGU: Measuring atmospheric neutrino oscillations at the South Pole

Very large volume neutrino telescopes (VLVNTs) observe atmospheric neutrinos over a wide energy range (GeV to TeV), after they travel distances as large as the Earth's diameter. DeepCore, the low energy extension of IceCube, has started making meaningful measurements of the neutrino oscillation parameters $\theta_{23}$ and $|\Delta m^2_{32}|$ by analyzing the atmospheric flux at energies above 10 GeV. PINGU, a proposed project to lower DeepCore's energy threshold, aims to use the same flux to further increase the precision with which these parameters are known, and eventually determine the sign of $\Delta m^2_{32}$. The latest results from DeepCore, and the planned transition to PINGU, are discussed here.