Why is radar hard to detect stealth aircraft while satellite telephones easily capture signals below the thermal noise floor?

Question

Why is radar hard to detect stealth aircraft while satellite telephones easily capture signals below the thermal noise floor?

In: Engineering

Answer 1

Stealth aircraft are specially designed to reflect radar signals in the wrong direction, and absorb some of it too (Meaning the few signals that are reflected back will be much weaker). Most modern military radars can be adjusted to detect stealth aircraft, the problem is that it significantly increases the chances of false positives as the noise floor is much lower. So things like birds start showing up as objects on the radar.

Satellite phones only listen on a specific frequency. So they do not need to search for tiny dots on a radar return, they just tune in on whatever satellite they’re programmed to.