"JOURNAL OF RADIO ELECTRONICS" N 1, 2002

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VECTORIAL EXPOSURE TO RADIATION OF A FOREST CANOPY

V. P. Yakubov*, E. D. Telpuchovskiy*, V. L. Mironov**, V. B. Kashkin**
*Tomsk State University, **Krasnoyarsk Scienific Centre of Siberian Branch of RAS

Received January 2, 2002

The results of experimental study of the effects observed when the radio wave propagates through the forest canopy are presented. A transmitting aerial was mounted on top of the tower to provide for far field zone at the upper boundary of the canopy. Receiving aerials were placed near the ground surface inside the canopy. Especially designed receiving aerials were used to ensure registration of the amplitude and phase at the same point in space for all the vector electromagnetic field components. The electromagnetic field generated inside the canopy was scanned horizontally for both the vertical and the horizontal polarization states of the incident wave, at two frequencies of 200MHz and 1275MHz. A regular interference picture for the measured electromagnetic field has been discovered. This effect can be attributed to two, earlier observed, dominant mechanisms of radio wave propagation through the forest canopy. The first mechanism mainly involves the wave paths through the canopy while the second one uses the wave paths over the upper boundary of the forest canopy. The experiment has been conducted at the test site of the Sukachev Institute of Forest, Krasnoyarsk Science Center, Siberian Branch of the Russian Academy of Sciences.

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