Short Range Echoes with Short Waves

The authors have made an examination of short range echoes by means of special signals transmitted from the high-frequency stations at Nauen (21,430 to 11,538 kc, or 14 to 26 m) and recorded photographically at Geltow. The echoes are sometimes blurred and sometimes repeated at fairly regular intervals, indicating multiple reflection between the ground and a reflecting layer. In one case the height of this layer is estimated to be about 1,500 m. The character of the echoes may change radically within a few seconds. General agreement is found between the authors´ observations and those of Taylor and Young and also those of Hoag and Andrew. The bearing of the echoes on radio communication is discussed and a number of oscillograms are reproduced.