  Providing an early warning of a galactic supernova using neutrino signals is
of importance in studying both supernova dynamics and neutrino physics. The
Daya Bay reactor neutrino experiment, with a unique feature of multiple liquid
scintillator detectors separated in space, is sensitive to the full energy
spectrum of supernova burst electron-antineutrinos. By deploying 8 Antineutrino
Detectors (ADs) in three different experimental halls, we obtain a more
powerful and prompt rejection of muon spallation background than
single-detector experiments. A dedicated supernova online trigger system
embedded in the data acquisition system has been installed to allow the
detection of a coincidence of neutrino signals within a 10-second window, thus
providing a robust early warning of a supernova occurrence within the Milky
Way.
