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Estimating TOF by parameter estimation of double exponential model

The notion of estimating ultrasonic pulse's TOF (time-of-flight) by estimating the parameters of double exponential model is introduced. The TOF of ultrasonic pulse comes down to the function of exponential terms' coefficients in the double exponential model, and can be estimated by the least square method with very little computational load. The simulations show that the performance of the method proposed in this paper is close to the cross-correlation method. Because of its very small computational load, this method can be implemented in the embed system.