Time Domain Holography and Instantaneous Active Intensity for Tracking of Transient Power Radiating Regions on Tyres

To ensure that vehicles meet the ISO 362 pass - by requirements before they are introduced in the market their transient noise radiation must also be tested under laboratory conditions. The paper describes a Time Domain Holography based method for localization, quantification and ranking of sound generating regions on vehicles under run-up (i.e. non-stationary) conditions. A case study on a tyre illustrates some of the possibilities with the new technique.