How can I make a velocity radar like this:

In counter strike source what commands do I type in the console?
How can I make a velocity radar like this:

In counter strike source what commands do I type in the console?
Not entirely sure what you mean by "velocity radar", but you can try Cl_showpos 1 which will n not only display your current posision but also display velocity.
To make life easier you can create a file called autoexec.cfg in your cstrike/cfg/ directory and write there the commands that you want and when you open CS:Source, the console commands would be run automatically.
I hope this helps.