Homemade synthetic aperture radar – Henrik's Blog
hforsten.com
hforsten.com
An interesting application of CW radar - http://hforsten.com/heartbeat-detection-with-radar.html
At 45 years old I feel like I've learned quite a bit, but when I read stuff like this I wonder if there are enough years left in my life to learn what to takes to put something like this together.
I will say that the little CW doppler radar boards are fun to tinker with. You can get them on amazon for <$10 shipped, power them with 5 volts and just wire the output to a microphone jack.
https://www.amazon.com/SMAKN-Microwave-10-525GHz-Doppler-Det...
This is what a coin toss over a 10GHz doppler device sounds like: https://www.youtube.com/watch?v=8riretP8ylE