Question

Two satellites at an altitude of 1200 km are separated by 28 km. If they broadcast 3.6-cm microwaves, what minimum receiving-dish diameter is needed to resolve (by Rayleigh’s criterion) the two transmissions?

Short answer

The minimum diameter of the receiving dish is 1.88m

Step-by-step solution

Rayleigh’s criterion

According to the Rayleigh criterion for the diffraction limit to resolution, two images are only resolvable when the center of one's diffraction pattern is directly over the first minimum of the other's diffraction pattern.

Minimum diameter of the receiving-dish

Given values;

The minimum receiving-dish diameter;

Hence, the minimum diameter of the receiving dish is 1.88m.