The meaning of the slope will depend on the problem under analysis. But roughly speaking, the steeper the curve is, the less power it will have at higher frequencies. Although it is possible to establish a rate of decay of high frequencies, in practice peaks arise. These can be due to noise, or even be a characteristic of the signal under analysis. If you are going to work with filters, the faster the decay the better.

You can understand well the sence of SPD taking into account its periodic continuation together with its mirror reflection.

Hi Sukriti Hans , how are you ?

Please, could you put a figure to illustrate your question ?

Best regards,

After removing any dc offset, the position of the tallest peak gives the characteristic frequency. Now, the slope of this peak would be determined by all the factors leading to the broadening of this peak. The obvious and universal reasons are statistical uncertainty in the data, time resolution of the data collected and exposure time of the data collection. The more specific factors would depend upon the data which is being collected (in experiments) or generated (in simulations). For example, in spectroscopy this broadening in the frequency spectrum would correspond to a broadening in the wavelength spectrum, of course, which might be a result of Doppler broadening, Zeeman splitting and a small contribution due to the uncertainty principle so on.

Fabrício Gerônimo Simões Silva

The attached is the 2D-PSD obtained from the AFM image.

You can refer to this image.

Bruno Rodrigues de Oliveira

Thanks for your answer.

Though I am looking for the slope of PSD obtained from any AFM image of a regular pattern.

Gamlet S Khanyan

Okay I will look into that.

Thanks for the response.