  The CALICE collaboration has constructed a highly granular hadronic sampling
calorimeter prototype with small scintillator tiles individually read out by
silicon photomultipliers (SiPM) to evaluate technologies for the ILC. The
imaging capability of the detector allows detailed studies of the substructure
of hadronic events, such as the identification of minimum ionizing track
segments within the hadronic shower. These track segments are of high quality,
so that they can be used for calibration, as an additional tool to Muons and to
the built-in LED system used to monitor the SiPMs. These track segments also
help to constrain hadronic shower models used in Geant4. Detailed MC studies
with a realistic model of an ILC detector were performed to study the
calibration requirements of a complete calorimeter system. The calibration
strategy was tested on real data by transporting calibration constants from a
Fermilab beam test to data recorded at CERN under different conditions.
