Preliminary Analysis of the Data of the Sudden Disturbance of Lower Ionosphere at Yunnan Observatory

The SPA data recorded in the Clock Room of Yunnan Observatory from Mach in 1982 to May in 1985 are added up and compared with those of the corresponding period obtained at Shanxai observatory and published in SGD.In addition,the SPA data are also compared with the data of the radio bursts and H-alpha solar flares obtained at Yunnan Observatory in the corresponding period.