Pass-by measurements using array techniques

Pass-by measurements on streets according to ISO-11819-1 are difficult to perform if traffic density is high. In that case the cars are often too close to fulfill the −6 dB criteria for the level between cars for a valid measurement. To overcome this difficulty array techniques are used to separate even close sound sources. Measurements are presented with multiple cars using array techniques and compared with standard single car measurements. Multiple microphone configurations are optimized, tested and combined with a source separation algorithm in order to resemble the results of single car measurements even with dense traffic.