The two transpolar shortwave time signal circuits,Moscow and Irkutsk to the Great Wall Station in Antarctica, are used to study the fading characters for shortwave long circuit.

为了极区的短波长电路的特性，在南极长城站收测莫斯科、依尔茨克的短波授时台信号，并给出各频率对应的深度、率、均持续时间等参数的统计特征和幅度分布曲线。