Method and system for determining the speed of sound in a fluid within a conduit

A system for measuring the speed of sound c in a fluid contained within an elongated body, the sound traversing the elongated body substantially along a direction aligned with the longest axis of the elongated body, the sound causing a momentary change in pressure in a portion of the fluid as the sound traverses the portion of the fluid, the system comprising:

• a) means for providing at predetermined locations an array of at least two sensors distributed along the elongated body, each sensor for discerning and signaling spatio-temporally sampled data including information indicating the pressure of the fluid at the position of the sensor;
• b) means for acquiring the spatio-temporally sampled data from each sensor at each of a number of instants of time;
• c) means for constructing a plot derivable from a kω plot, using a technique selected from the group consisting of spectral-based algorithms, such as the Capon method or the MUSIC method, in which a spectrum-like function of the speed of sound is formed, and parametric methods of solution, such as the deterministic maximum likelihood method;
• d) means for identifying in the kω plot a spectral ridge, and determining the slope of the spectral ridge;
• and
• e) means for determining the speed of sound assuming a relation between the speed of sound and the slope of the spectral ridge.