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4.1.6 Recognition and Processing of Mirage Peak (Ghost)
Recognition of phantom peaks (ghosts): The ghosts on the curve do
not cause obvious loss (such as the upper right figure); the distance
between the ghosts and the beginning of the curve is a multiple of the
distance between the strong reflection event and the beginning, which
is symmetrical (such as the lower right figure).
Eliminate phantom peak (ghost): select short pulse width, increase
attenuation in strong reflection front end (such as OTDR output). If the
event causing ghost is located at the end of the optical fiber, it can
"bend" to attenuate the light reflected back to the beginning.