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If a Return Echo Arrives After the Allocated Pulse Interval Then
By BYJU'S Exam Prep
Updated on: September 25th, 2023
If a return echo arrives after the allocated pulse interval. Then,
Choose the right answer to the question if a return echo arrives after the allocated pulse interval. Then, from the following options along with the detailed explanation.
- the receiver may be overloaded.
- the target will appear closer than its actual position.
- the return echo may interfere with transmitter operation.
- none of the above
Table of content
Answer – B. the target will appear closer than its actual position
If a return echo arrives after the allocated pulse interval. Then, the target will appear closer than its actual position.
Solution
The detailed solution to the question of a return echo arrives after the allocated pulse interval. Then, provided here.
The transmitted signal’s pulse width (or pulse duration) is the length of time between each pulse, which is typically measured in microseconds.
The pulse width needs to be long enough for the radar to emit enough energy for the reflected pulse to be picked up by the receiver. The sum of the transmitter’s peak output power and the transmission time determines how much energy may be transmitted to a far-off target. Therefore, pulse width limits the range at which one can detect a target.
Pulse width also limits range discrimination, the radar’s ability to tell apart two targets close to one another. The range resolution is roughly equivalent in distance to half of the pulse duration times the speed of light when observed by radar with an unmodulated pulse at any range, with similar azimuth and elevation angles.
The radar’s dead zone at close ranges is likewise governed by pulse width. The receiver input is blanked while the radar transmitter runs to prevent overloading or to harm the amplifiers.
Most radar systems continually produce pulses to develop a perceptible echo, and the system’s function determines the pulse repetition rate. Every time a new pulse is broadcast, an echo from a target will be “painted” on display or integrated into the signal processor, strengthening the return and facilitating detection.
The target looks closer than it is if the returning echo comes after the designated pulse interval.
Hence, Option (B) is the correct answer.
