Seeing stealth aircraft isn't about resolution. The key to seeing something with radar is signal-to-noise ratio. From the article: "it becomes possible to me

Seeing stealth aircraft isn't about resolution. The key to seeing something with radar is signal-to-noise ratio. From the article: "it becomes possible to measure the properties of individual raindrops greater than 0.5mm in diameter due to the low concentration of such drops in naturally occurring cloud systems and the overwhelming dominance such drops have on the measured radar reflectivity when present in a field comprised of smaller particles." It's easy to distinguish an airplane from something with a similar sized signature, say an insect, since the airplane moves at 1000knots instead of 1, but you have to be able to see it through the noise. That's tricky. If you use a radar like this (high power, really narrow beam) you might be able to see a stealth plane. But, you'd have to know where to point it. Therein lies the challenge.