Physical Measurements from Discrete

2D Discrete Fourier transform can be obtained by the formula given by:

The function(image) has a size of NxM. Using the function fft2, it performs the fourier transform along the rows and ftt performs the fourier transform along the columns.


Answers to questions:

a) In a light bulb a Fmax of the llight bub is 120 Hz. To get the threshold sampling interval, use the equation T= 1/(Fmax*2) which is equal to the value 4.16ms.


b) Increasing the total number of samples N increases the height because you increase the number of samples.

Figure1. The left image has lower N and the right image has higher N

c) Decreasing sampling interval Δt decreases the frequency of the signal (if you decrease the total time T) thus shifting the peak to a lower value and increasing the peak (if you increase the total number of samples N).

Figure 2. The left image has the lower dt

d) Fixing time interval T but increasing the N increases the height of the peak (same as the answer to question b).

In this activity, I will give myself a grade of 8.5 for the reason that few of my answers came from my collaborator.

Collaborator:

Rafael Jaculbia