Top quark reconstruction in ATLAS

ATLAS detector with powerful calorimetry and precise tracking system has the excellent capabilities to investigate the top quark sector of SM. To exploit fully an ATLAS potential and benefit from high LHC top quark production cross section, one needs to define a reconstruction strategy for accessing top quark physics in a most precise way. Jet finding, jet energy calibration and jet tagging in ATLAS will be described, together with constraint fits for restoring top quark kinematical parameters. Systematic errors introduced by reconstruction will be discussed. Quick top physics measurements during ATLAS detector commissioning will also be considered.