The improvement of acoustic compatibility of a city sodar antenna

Wide application of sodars for ecological use in cities is restrained now due to a high spurious radiation level of modern sodar antennas, especially at the angle of about 90/spl deg/ with respect to its main lobe. By an example of the developed sodar horn-reflex antenna, the possibility of essential improvement of its acoustic compatibility necessary for using it in cities is shown. It is shown that the improvement can be achieved as a result of the analysis of mechanical characteristics of an acoustic antenna construction with subsequent tuning out mechanical resonance frequencies of the construction at the expense of variations of its mass and rigid properties. The results of numerical experiments confirm reality of the supposition about the possibility to increase the level of suppression of extraneous sodar antenna radiation up to 60 dB on the basis of the proposed procedure.