1. A method for real time matched field, processing to locate the position of an acoustic source, said method comprising the steps of: providing at least one linear array, the linear array including equispaced hydrophones; providing a processor; measuring acoustic data from at least one of the equispaced hydrophones; providing a first data input from said measuring step; transforming by the processor the first data input to a frequency domain with a Fourier transform to a set of continuous time samples from said at least hydrophone; defining a data vector from the frequency domain; determining at least one replica vector representing a predicted value of the at least one sensor output for a specific frequency; averaging multiple replica data sets of the at least one replica vector to the first data input; determining a closest matched data set to the first data input from said averaging step; and outputting an ambiguity surface as a set of numbers in a range between zero and one with a highest value corresponding to the position of an acoustic source.