Frequently Asked Questions
Question I have a small microphone array, let's say it is a 10 cm diameter circular array with eight microphones. I would like to configure ODAS to provide me with both direction and distance of a sound source, which would be a few meters away from the array. Is this something I can achieve?
Answer Short answer: no. ODAS will provide you with the direction of arrival, but not the distance. This limitation does not come from the software, but from antenna theory. Since the microphones are close to each other (~0.1m) relatively to the distance between the source and the microphone array (~2-3m), the far field effect applies. The far field effect says that for close sensors, only the direction of arrival can be estimated accurately with phase differences obtained from the observed signals.
It is however possible to use multiple microphone arrays (spaced by a distance of the order of the distance between the source and the array) to perform triangulation and estimated the 3D absolute position of a sound source. Here is an article that demonstrates this scenario to localize and track flying drones.