The state of the art sensor is the so called USP. The three dimensional ½ inchUSP regular probe consists of three orthogonally placed Microflown acousticparticle velocity sensors and a sound pressure microphone. The actual sensorconfiguration without its cap is less than 5×5×5mm! Any sound field isdescribed by two complementary acoustic quantities, the scalar value 'soundpressure' and the vector value 'particle velocity'. The Microflown is the onlysensor that can measure the acoustic particle velocity directly. Thanks to theunique properties of the USP probe all physical quantities, sound pressure andtri-axial particle velocity, can be measured directly, In order to get the 3DSound intensity vectors without any frequency limitations.
The sensor, its orientation and position is fully tracked in 3D.The opticaltracking system is based on monitoring a defined measurement space using astereo camera. Each camera is equipped with an infrared (IR) pass filter in frontof the lens, and a ring of IR LEDs around the lens to periodically illuminate themeasurement space with IR light. This light is not visible to the human eye andits intensity is completely safe for human beings to work with. The sensor isequipped spherical marker, with embedded retro-reflective markers, whichreflect the incoming IR light. The IR light reflections are detected by the stereocamera, and the tracking system translates them to exact 3D coordinates alongwith the sensor orientation.
All results can be visualised on an interactive 3D model. This model can be easily created with the 3D Shape Editor. 3D models can also be importedfrom a veriety of supported files formats e.g CAD, SkechUp.