Using three meteorological factors such as temperature, average wind speed, relative humiditymeasured by automatic weather station in real - time as the basic parameters, the critical meteorological index for freezing and melting of wind sensor in automatic weather station was established. The wind - driven sensor antifreezing heating device was controlled for automatic operation through the PC - RS232 communication interface, ATmega8 - based single - chip and op toelectronic isolation circuit, which would realize the goal of the wind sensor antifreezeing p rotection in automatic weather station.

Based on the wind speed and wind direction data observed in routine and automatic weather station in 2003 in Pingliang city，the statistical comparison of observed and extreme values in routine and automatic weather station from January to December in 2003 has been analyzed. The results show that in the influence of the systematic error of instruments and observational time error，the daily mean wind speed of routine station is 0. 4 m/ s less than automatic weather station，and the corresponding wind directions are nearly 40% in both routine and automatic weather stations，the ratio of disagreement over two directions is 4%..