On Thursday, January 16, 2020 at 3:25:49 PM UTC-8, Jeff Liebermann wrote:
Autonomous vehicles, high end automobiles, and even some prototype
traffic signals, all use some form of radar to detect and identify
objects. The problem is that these have a less then perfect score
even under ideal conditions. I thought it might be of general
interest to see how the technology works and how far it has
progressed. Note that they only show the results of a side view of
the bicycle, with nothing shown for front and rear views.

Incidentally, you might consider building or buying a 77GHz corner
cube or spherical retroreflector so that you and your bicycle will be
more visible to vehicular radar. The common bicycle reflector would
work if the reflectors were metalized to reflect RF, and somewhat
larger (about 1 wavelength at 77GHz wide or 4mm) per cell.

"Algorithms to Antenna: Classifying Radar Micro-Doppler Signatures"
https://www.mwrf.com/technologies/systems/article/21120548/algorithms-to-antenna-classifying-radar-microdoppler-signatures
https://www.mathworks.com/help/phased/ref/backscatterbicyclist.html

"Wearable radar reflectors"
https://patents.google.com/patent/US20150029050

Soon, everyone will be wearing radar reflectors. After the initial
panic, fad, craze, and hype die out, they'll probably be made
mandatory as yet another safety device. You read it on RBT first.

These radars are so sensitive that you can pick up you waving an arm. So you don't have to worry about them picking up a moving bicycle.