New approaches to the investigation of the array directivity pattern in the natural environment

The problem of directivity pattern measurement in the natural environment is studied. The time delay spectrometry technique modified by the authors is used to provide measurements in the presence of surface reflections and high noise level. An optimal combination of hardware and software data processing allowed to gather in short period of time a set of 8/spl times/10/sup 7/ complex values of the array directivity pattern depending on frequency, azimuth and elevation angles. The methods elaborated in order to perform visualization and preliminary analysis of that data include complex approximation, computer animation and 3D photorealistic imaging. It is shown that these methods facilitate the perception of the data and serve a good background for the choice of methods and directions of further numerical analysis. The possibility of the array elements diagnostics is demonstrated.