How to perform one-dimensional power spectral density(PSD) analysis to filter out high-frequency noise in surface profile z(x,y) data ?

The problem on the data processing of surface morphology of abrasive belt which I need to solve is that: The height value matrix z(x,y) has 142*108 points, there are 142 points in x-direction, and the pitch is 0.01 mm, and there are 108 points in y-direction, and the pitch is 0.01 mm, too. The unit of height value z is also mm. The height value matrix (H.txt) has been attached.The surface morphology of abrasive belt is shown as below.

What I want to do is calculate one-dimension Power Spectral Density (PSD) function for abrasive belt surface from surface profile z(x,y). The picture I want can refer to Fig.6 of the attached file (Three-dimension surface characterization of grinding wheel using white light interferometer.pdf).

So how can I get the result of PSD analysis for surface toporgraphy of abrasive belt ?