Do you ever watch your local TV weather report and find yourself overcome with excruciating jealousy due to the fact you don't have your own personal Doppler radar? Of course you do. It's a normal reaction. Why do they get all that neat radar gear while you remain utterly blind to the velocities at which clouds — let alone everyday objects — are speeding to or away from you?
Thankfully, our friends at MIT's Open Course Software program, which makes MIT coursework available to the general public free of charge, wants to help you fix your depressing Dopplerlessness. The online program recently made their student materials available from last year's three-week undergraduate lab called "Build a Small Radar System Capable of Sensing Range, Doppler, and Synthetic Aperture Radar Imaging."
The coursework leads students through the radar building process in order to "generate student [interest] in applied electromagnetics, RF, analog, signal processing, and other (often tedious) engineering topics by building a capable short-range radar sensor and using it in a series of field tests."
You had us at "tedious!"
This particular Doppler radar design utilizes regular coffee cans as a primary component. The design may not be so good at predicting coming weather patterns over a general landmass, but it will perform as a good makeshift "radar gun," as can be seen in this video:
(Or you can easily download the whole course in one 81 MB shot).
Unfortunately, this small scale DIY Doppler design will probably not fulfill all your local weatherman dreams. It could help you fulfill your highway patrol fantasies as you deliver warnings to neighbors who creep ever so slightly over the speeding limit.
And that's a close second.