Pulse repetition frequency, Beam width, Relationship between PRF and range

Pulse repetition frequency, Beam width, Relationship between PRF and range

Pulse repetition frequency PRF
PRF – pulse repetition frequency
Or, PRR – pulse recurrence rate.
Number of pulses sent out per second.
Radar scanner sent out radar pulse.
Normally 500 to 4000 pulses per second.
PRF varies with range scale.

Beam width
Width of a transmitted radar beam.
Two types: HBW, VBW
Horizontal beam width: Horizontal angle at the scanner between the leading edge and trailing edge.
Vertical beam width: Vertical angle at the scanner between the upper edge and lower edge.

Relationship between PRF and range
Picture resolution of a RADAR set is governed by RPM-PRF relationship.
In short range, at a constant RPM, PRF – 2000.
In long range, at a constant RPM, PRF – 1000.
Because in long range, it’s not possible a greater interval between pulses to go and come back, results in low PRF.
Therefore, long range have a low PRF and short range have a high PRF.
Due to this,
In short range, picture quality will be good.
In long range, picture quality will not be good.