3. The method of claim 2 wherein the model parameters are represented by the following: ω j = λ j * , T j = 2 ⁢ π / ω j = 2 ⁢ π / λ j * , α j = ∑ t = 1 N ⁢ q t ⁢ ⅇ - ⅈ ⁢ ⁢ λ j * ⁢ t , ⁢ A j = 2 ⁢  α j  ⁢ ⁢ and ⁢ ⁢ φ j = arg ⁢ ⁢ ( α j ) .
2. The method of claim 1 wherein the model is represented by the following: q t = ∑ j = 1 q ⁢ α j ⁢ exp ⁡ ( ⅈ ⁢ ⁢ t ⁢ ⁢ λ j ) + ξ t .