  A gravitationally lensed gamma-ray burst (GRB) would appear as multiple
bursts with identical light curves, separated in time and differing only by the
scaling of their amplitudes. However, noise may make them difficult to identify
as lensed images. Furthermore, faint, intrinsically similar, yet distinct light
curves may be falsely identified as lensing events. In this paper we develop
two statistical tests to distinguish noisy burst light curves. We use Fourier
analysis techniques to analyze the signals for both intrinsic variability and
variability due to noise. We are able to determine the noise level, and we
compare the bursts only at frequency channels that are signal dominated.
Utilizing these methods, we are able to make quantitative statements about
whether two bursts are distinct. We apply these statistics to scaled versions
of two subbursts of GRB 910503--- subbursts previously investigated by
Wambsganss (1993) using a different statistical test. We find that our methods
are able to distinguish these bursts at slightly smaller amplitudes than those
at which Wambsganss's method succeeds. We then apply our techniques to
``candidate" lensing events taken from the BATSE catalogue, and we find that
nearly all of them, except for the very shortest ones (durations $\aproxlt 0.3
~s$), are distinguishable. We therefore expect that a majority of bursts will
be disinguishable from one another.
