1. A method for determining turbulent boundary layer thickness, comprising the steps of: mounting a pair of sensors to a solid surface interfacing with a fluid at two separate stream wise locations; recording a voltage output from said pair of sensors; computing a real non-dimensional value of a correlation coefficient from said recorded voltage; independently determining a laboratory non-dimensional value of the correlation coefficient from laboratory data; and comparing the real non-dimensional value with the laboratory non-dimensional value to obtain a boundary layer thickness having a value which minimizes a difference between the values of the real non-dimensional value and the laboratory non-dimensional value.