  The identification of the electromagnetic(EM) counterpart of gravitational
wave(GW) trigger in the sky localization is a very difficult task because of
the large uncertainty. Two complementary approaches are used in order to search
for EM counterpart of GW signal with a typical large sky localization
uncertainty: wide-field tilling search on high probability GW region, e.g.
Gravitational Wave Inaf Team(GRAWITA) project or pointed search of selected
galaxies in high probability GW region, e.g. Distance Less Than 40 Mpc
survey(DLT40) project.
