Meteorological utilisation of horizontal microwave propagation measurements

A simple method, in real time, to detect an inversion layer in the lower atmosphere, can be that of monitoring horizontal microwave radiopropagation across the considered area, between two stations linked by radiowaves only during non-standard atmospheric conditions.Experimental results of the first three months of continuous measurements at 3cm, wave-lengths, are given for a path only over sea and for one only flat land.An attempt to find a connection with local meteorological ground data has shown a strong correlation between radio signal reception along super-standard distances and the water vapour pressure for the sea path. In this case, “radio ducting” seems to result from a steep monotonic decaying of the water content of the air.Radio measurements over the flat land path show radio ducting to be an almost nocturnal process. In this case, radiopropagation beyond the horizon detects temperature inversions caused by nocturnal cooling and, therefore, there is no correlation with meteorological ground data.Finally, the frequent presence of radio ducts (time efficiencies greater than 80% have been measured by the authors in certain periods of the year) could also be exploited by telecommunication users for inexpensive transmission, although not in real time, of pre-recorded data.