Which intensity is the location maximum averaged over the transmit time?

• A. Isptp
• B. Isppa
• C. Ita
• D. Imax

Answer: (B)

Think of intensity as described by where in space and how you average over time. The phrase “location maximum” means the strongest point in space, and “averaged over the transmit time” means you average during the actual pulse duration, not over the whole cycle.

So the quantity you get is the spatial peak value at the location of maximum intensity, averaged over the pulse length. This is known as spatial peak pulse-average intensity. That matches the idea of taking the peak at a location and then averaging across the transmit time of a single pulse.

The other options correspond to different averaging schemes:

• temporal peak at the spatial peak (no averaging),

• temporal average (averaging over the entire transmit cycle, including off times),

• maximum instantaneous anywhere (not averaged),

• and a combination like spatial peak temporal-average, which isn’t what’s described here.