When the depth of view is deep, PRF is ______.

When the depth of view is deep, PRF is ______.

• A. High
• B. Medium
• C. Very low
• D. Low

Answer: (D)

Echoes take longer to return from deeper targets, so the system must space pulses farther apart to give enough listening time. PRF is how often pulses are emitted, and a higher PRF would mean the next pulse is sent before deep echoes have finished returning, causing range ambiguity. By lowering PRF for deep imaging, you ensure the deepest echoes are captured unambiguously. Therefore, when the depth of view is deep, PRF is low. (For shallower imaging you can increase PRF to improve frame rate, but that’s not suitable for deep views.)

Echoes take longer to return from deeper targets, so the system must space pulses farther apart to give enough listening time. PRF is how often pulses are emitted, and a higher PRF would mean the next pulse is sent before deep echoes have finished returning, causing range ambiguity. By lowering PRF for deep imaging, you ensure the deepest echoes are captured unambiguously. Therefore, when the depth of view is deep, PRF is low. (For shallower imaging you can increase PRF to improve frame rate, but that’s not suitable for deep views.)