Azimuthal duct mode detection in experiments are particularly beneficial for designing ad-vanced fans and evaluating passive/active noise reduction methods. In this paper, we propose a new mode detection method based on compressed sensing, which can largely reduce the sensor numbers required by Shannon-Nyquist sampling theorem. The success of the com-pressed sensing methodology is based on the fact that incident waves are sparse in spinning modes and the sensors are located randomly. However, when the sensor number is small, the mode detection maybe not successful for many sensor displays. Therefore, besides introduc-ing a more straightforward way of applying compressed sensing method to duct mode detec-tion, this paper also studies properties of the sensor location in order to obtain the expected good mode detection results in the real experiment. The studies of sensor location properties are based on both Monte Carlo simulations and a real experiment test. This makes it quite promising to apply much less sensors in a real experiment and detect mode successfully with compressed sensing algorithm.
