Conformal Mapping Using SONAH

Conformal mapping provides a map of sound pressure, sound intensity or particle velocity directly on the actual surface geometry of arbitrary surfaces. Other mapping methods are typically restricted to work on simplistic planar (or spherical) approximations to the source geometry either for practical reasons or due to algorithmic limitations Using a local SONAH approach the system calculates levels at the source surface based on a set of patch measurements, for example, from the hand-held array with integrated position detection device, made at accessible positions distributed around the source.

In comparison with maps measured or calculated at short distances away from the source, maps at the actual source position provide better resolution and leave less room for misinterpretation. Conformal maps are also more easily communicated to non-acousticians.

Since the measurements can be made at any accessible place close to the object, the time spent on special preparation of the source to the test is minimal. For example, when mapping an engine on a test bench, usually significant time is spent changing the routing of fuel lines, exhaust, electronic wiring etc., to provide unhindered access to a complete face. This is no longer necessary.

Since particle velocity on top of a hard surface corresponds closely to the actual vibration of the surface itself, the results can directly be used for correlation with structural models.