A comparison of statistically optimized near field acoustic holography using single layer pressure-velocity measurements and using double layer pressure measurements.

Statistically optimized near field acoustic holography (SONAH) is usually based on the assumption that all sources are on one side of the measurement plane whereas the other side is source free. An extension of the SONAH procedure based on measurement with an array of pressure-velocity probes has recently been suggested. An alternative method uses a double layer array of pressure transducers. Both methods make it possible to distinguish between sources on the two sides of the array and thus suppress the influence of extraneous noise and reflections coming from the "wrong" side. This letter compares the two methods.