Visualization of 3-dimensional beam patterns using the SGI workstation

The beam pattern of an acoustic source or receiver is a 3D object, representing the response of that receiver to energy arriving from any direction. It is common practice to display the 3D beam pattern as a series of 2D polar or rectangular plots representing vertical beam patterns for a fixed horizontal steer direction or horizontal beam patterns for a fixed vertical steer direction. The complete 3D pattern is often deduced, at the expense of some mental effort, from a collection of these 2D displays. Based on an existing computer program, gbeam, with the computational and graphical capabilities of the Silicon Graphics Iris (SGI) workstation, a realistic picture of 3D beam patterns can be displayed. This paper describes the SGI workstation, the gbeam program, and their applications within the Interactive Multidimensional Acoustic Trainer (IMAT), and presents several examples of typical beam patterns