  From the launch of the Fermi Gamma-ray Space Telescope to July 9, 2010, the
Gamma-ray Burst Monitor (GBM) has detected 497 probable GRB events. Twenty-two
of these satisfy the simultaneous requirements of an estimated burst direction
within 52^\circ of the Fermi Large Area Telescope (LAT) boresight and a low
energy fluence exceeding 5 $\mu$erg/cm^2. Using matched filter techniques, the
spatially correlated Fermi/LAT photon data above 100 MeV have been examined for
evidence of bursts that have so far evaded detection at these energies. High
energy emission is detected with great confidence for one event, GRB 090228A.
Since the LAT has significantly better angular resolution than the GBM,
real-time application of these methods could open the door to optical
identification and richer characterization of a larger fraction of the
relatively rare GRBs that include high energy emission.
