  We combine single- and two-photon interference procedures for characterizing
any multi-port linear optical interferometer accurately and precisely. Accuracy
is achieved by estimating and correcting systematic errors that arise due to
spatiotemporal and polarization mode mismatch. Enhanced accuracy and precision
are attained by fitting experimental coincidence data to curve simulated using
measured source spectra. We employ bootstrapping statistics to quantify the
resultant degree of precision. A scattershot approach is devised to effect a
reduction in the experimental time required to characterize the interferometer.
The efficacy of our characterization procedure is verified by numerical
simulations.
