Which term is defined as the reception from a previous pulse that may coincide with closer targets?

Which term is defined as the reception from a previous pulse that may coincide with closer targets?

• A. Echo bleed
• B. Ghost echo
• C. Range aliasing
• D. Ambiguous Return

Answer: (D)

Ambiguous return happens in pulsed radar when echoes from an earlier pulse are still arriving while the receiver is processing the current pulse. If that old-pulse echo lines up in time with echoes from closer targets, you can’t tell which echo came from which pulse, so the range information is unclear. This binding of a previous-pulse return to a current-time window is what the term describes. In practice, this means a target’s true range can be confused with a return from a prior pulse, or you may see an apparent near target that’s really an old echo. Controls like increasing the pulse repetition interval or using processing techniques help separate these returns and remove the ambiguity. Echo bleed involves spillover into adjacent range bins, ghost echoes are false duplicates from processing or multipath, and range aliasing is a misassignment of range due to sampling limits—these don’t capture the specific situation of a previous-pulse echo overlapping with a nearer target.

Ambiguous return happens in pulsed radar when echoes from an earlier pulse are still arriving while the receiver is processing the current pulse. If that old-pulse echo lines up in time with echoes from closer targets, you can’t tell which echo came from which pulse, so the range information is unclear. This binding of a previous-pulse return to a current-time window is what the term describes.

In practice, this means a target’s true range can be confused with a return from a prior pulse, or you may see an apparent near target that’s really an old echo. Controls like increasing the pulse repetition interval or using processing techniques help separate these returns and remove the ambiguity.

Echo bleed involves spillover into adjacent range bins, ghost echoes are false duplicates from processing or multipath, and range aliasing is a misassignment of range due to sampling limits—these don’t capture the specific situation of a previous-pulse echo overlapping with a nearer target.