Radar Question About Doppler Frequency

[4190help]

Homework Statement

How to find the radar resolution?

Homework Equations

Doppler frequency = 2v/wavelength
f = 2B
R = ct/2

The Attempt at a Solution

I don't know how to take the length of the aircraft into consideration.
I only know how to calculate the doppler frequency but not the range resolution
Give me some help!
My teacher gave me a wrong when I said increase the directivity of the radar in part 2. Why?

 

[marcusl]

Homework Statement

How to find the radar resolution?

Homework Equations

Doppler frequency = 2v/wavelength
f = 2B
R = ct/2

The Attempt at a Solution

I don't know how to take the length of the aircraft into consideration.
I only know how to calculate the doppler frequency but not the range resolution
Give me some help!

That's "Can someone help me, please?" Asking for help is always nicer than commanding like you owned us. You don't.

Range resolution tells you the granularity with which you can tell position. This is not the same as aircraft length. A 100 m resolution would allow you to say, e.g., that the target is located between 5,100 and 5,200 m away. Try re-reading your materials, and use this hint: range resolution is determined by the pulse bandwidth.

My teacher gave me a wrong when I said increase the directivity of the radar in part 2. Why?

Because it's an incorrect answer. Higher directivity results in a narrower, higher-gain beam. This improves sensitivity (that is, the strength of the signal) and it improves angular resolution (that is, pointing resolution), but does not affect range resolution.