The correlation properties of a directly carrier-modulated code sequence modulation signal are exploited to investigate sound propagation in turbulent air. An experiment is described in which the correlation properties of the spread spectrum signal are demonstrated and are used to calculate accurate times of flight that compare well with sonic anemometer measurements of speed of sound. The results illustrate that a directly carrier-modulated code sequence modulation system can provide significantly improved ways of measuring sound propagation outdoors. Moreover, the technique directly measures wind speed. This can be used to compensate the time of flight thus allowing the measurement of acoustic impulse responses in non-stationary media, for example outdoors, where reliable measurements have previously been difficult to obtain.
Click to purchase paper as a non-member or login as an AES member. If your company or school subscribes to the E-Library then switch to the institutional version. If you are not an AES member and would like to subscribe to the E-Library then Join the AES!
This paper costs $33 for non-members and is free for AES members and E-Library subscribers.