Measuring the rotation curve of galaxies

[accdd]

What should I learn to make astrophysical measurements from open data?
Suppose I want to measure the rotation speed of galaxies to generate galactic rotation curves like these: https://en.wikipedia.org/wiki/Galaxy_rotation_curve
What should I do and what should I learn?
I think I should get some data from a radio telescope, measure the distance to the galaxy and compare the emission frequencies of the left and right sides. Anything else?
How is everything done in a scientifically correct way?
I have chosen "I" as the level of the question, but any answer of any level is welcome, even "B" and "A"
Thank you

 

[strangerep]

What should I do and what should I learn?

You could start with this paper which summarizes what has been analyzed from the SPARC database -- which already contains a large body of data for the measurements you wanted. I.e., you'd learn a lot just by acquiring an understanding of how the SPARC database was produced, much of which is explained in the literature by Stacy McGaugh and in his courses.

If you follow its references backwards, you'll eventually get into (i.e., devoured by) the vast body of theory about measuring astrophysical distance, spectral analysis, and so on.

There's encyclopaedic textbooks like Binney & Tremaine. Also Bovy's Interactive Galaxies Textbook.