  The IceCube Neutrino Observatory is a 1 $km^{3}$ detector currently under
construction at the South Pole. Searching for high energy neutrinos from
unresolved astrophysical sources is one of the main analysis strategies used in
the search for astrophysical neutrinos with the IceCube Neutrino Observatory. A
hard energy spectrum of neutrinos from isotropically distributed astrophysical
sources could contribute to form a detectable signal above the atmospheric
neutrino background. A reliable method of estimating the energy of the
neutrino-induced lepton is crucial for identifying astrophysical neutrinos. An
analysis is underway using data from the half completed detector taken during
its 2008-2009 science run.
