Integration of the far field diffraction of plane noise barriers by mapping their surface

A plane noise barrier is separated into regions of 'positive' and 'negative' influences. The effect of these influences is studied at a control point. Zero influence lines are located between 'positive' and 'negative' regions and have the property that the boundaries of the barrier have no effect on their function. The analysis into the characteristics of equi-influence lines was based on the diffraction theory which includes the interference phenomena. In this context the influence of these lines is plotted on the surface of the barrier. The work is restricted to the 'Far Field Theory' as postulated by Born and Wolf (1970) from which a technique was devised. This technique accounts for the influence of 'positive' and 'negative' regions. Experimental data based on the work of Maekawa (1974) agree with the order of results given in the paper. However, the approach presented here enables stationary mapping to be achieved on a wide range of barrier geometry.