In astronomical interferometry, what values do the points in the uv-plane have?
I was struggeling to understand 2080's question, so I looked up the given reference which might be worth re-quoting:

With this additional information in hand, the question (initially) seemed to be mainly about the  interpretation of 2D discrete Fourier trafo, using the terms of astronomy.
If that interpretation was correct, I suggest e.g. http://bigwww.epfl.ch/demo/ip/demos/FFT/ which offers an intutive and interactive approach to Fourier transformation in general.
Edit: The question has been edited, and the main issue seems to be How do I get these values $V(u,v)$ from the signals $T(x,y)$ of my telescopes? I write &quot;seems&quot; since I am not 100% certain that $T(x,y)$ are indeed the signals of the telescope.
What I know from Math behind a uv plot in interferometry? is that the units used in the u-v-plane are wavelength, e.g. in meters.
References

Lecture by Jason Hessels on Radio Astronomy: The Techniques of Radio Interferometry I: Basics overs an introduction I found quite accessible.