Radar Equation for Distributed Targets - The Pulse Volume

• Thus far, we've derived the radar equation for a point target.
• This will work fine if you are interested in point targets such as airplanes
• However, in a thunderstorm or some area of precipitation, we do not have just one target (e.g., raindrop), we have many.
• Thus we need to derive a radar equation for distributed targets
• Before we do so, let's learn more about the radar pulse volume

RADAR PULSE VOLUME  

• First, let's simplify the real beam according to the diagram:

Q:  What does a "three-dimensional" segment of the radar beam look like?  -> 

Q:  What is the radial resolution of the pulse? 

In other words, what is the smallest radial distance that the pulse can occupy? 

HINT: remember that the pulse will be traveling out to a target, scatter off of it and then propagate back to the radar

So, what is the radial resolution for a given radar?? Answer

Back to the three-dimensional pulse volume.  

What is the azimuthal dimension of the pulse volume??  Answer

So, the "volume" of the pulse volume is:

For a circular beam, then q = f, the pulse volume becomes:

Q:  Does the pulse volume radial resolution change as you move away from the radar??  Answer

Q:  Does the pulse volume azimuthal resolution change as you move away from the radar??  Answer

Q:  How does one calculate the azimuthal resolution??  Answer

Let's take a look at the pulse volume and how it changes with range with real data.......