Question

Why are microwaves considered suitable for radar systems used in aircraft navigation?

Answer 1

Hint: RADAR stands for Radio Detection and Ranging. Microwaves struck the bulk of the range of radio frequencies. The wavelength of microwaves is smaller as compared to radio waves. When microwaves travel through the atmosphere, they can pass through it without any deviation.

Complete step by step answer:
The term microwave refers to any frequency between $300 MHz$ and $300 GHz$ correspond to wavelengths of $1 m$ to $1 mm$, respectively. Apart from very long-distance radars, such as coastal and ship-borne over-the-horizon and missile early warning radars, all radar systems use frequencies above $300 MHz$.
Radars send a wave of energy designed to reflect off an object and return to the receiver. The timing and change in the wave give you information on the object it reflects off. The longer the wavelength generally, the further you will send that wave, but lower the resolution as to the object information and therefore slower the feedback. For air traffic control around the country, knowing where the aircraft is within 10 or 20 feet is fine, however for a precision approach, you probably need a tighter range and faster updates. If you are going to track a fighter aircraft, a missile, or guide a high-speed missile to a target, you need excellent precision and very fast updates.

Note:
Longer range early warning radars designed to trace targets during a large area will use lower frequency radars (microwaves) within the UHF/VHF bands ($30-3000 MHz$). Fighter aircraft and missile control radars tend to be within the higher frequency X band ($8-13 GHz$).