Study on the time calibration method of the YangBaJing Hybrid Array

The YangBaJing Hybrid Array (YBJ-HA) is located at the Yangbajing international cosmic ray observatory, Tibet, China. It consists of 115 scintillation detectors (SDs) and 16 underground water Cherenkov muon detectors (MDA). Its main physical goal is to observe the $\gamma$ $\gamma $ -ray sources in the 100 TeV energy region, so the array must have very good pointing accuracy. To achieve this performance, the time response of the scintillator detectors must have high consistency. This paper introduces a characteristic plane method (offline calibration method) to calibrate the time of each scintillator detector and uses the moon shadow analysis results to test the time calibration accuracy.