  Based on the rate of gravitational-wave (GW) detections by Advanced LIGO and
Virgo, we expect these detectors to observe hundreds of binary black hole
mergers as they achieve their design sensitivities (within a few years). A
small fraction of them can undergo strong gravitational lensing by intervening
galaxies, resulting in multiple images of the same signal. To a very good
approximation, the lensing magnifies/de-magnifies these GW signals without
affecting their frequency profiles. We develop a Bayesian inference technique
to identify pairs of strongly lensed images among hundreds of binary black hole
events and demonstrate its performance using simulated GW observations.
