The Seeing at Gaomeigu in 2000 and 2001

The seeing were measured at the Gaomeigu in 2000-2001 with the DIMM-TSA (The differential image motion monitor with three sub-apertures).Each time the DIMM-TSA took 8ms exposure time for one image sample and 128 samples ware statistically to be one seeing record.During 14 nights the seeing ranged form 0.73" to 1.42" and the average seeing was 0.97". For the study of the turbulence characters at the Gaomeigu,4ms,8ms and 20ms exposure time were also used.The DIMM-TSA has three sub-apertures that could measure seeing in three directions simultaneously,and the effect of the wind speed and wind direction on seeing measurements is estimated.