Sensors 4 Flashcards
Pulse Characteristics?
- PW (Pulse Width); FOR RESOLUTION.
- PRF (Pulse repetition frequency) (Hz);
- Power output (KW); FOR MAX RANGE
- Pulse shape :FOR RANGE ACCURACY
Describe Pulse Width
Duration is measured in microseconds (1 microsecond = 1000’)
Measured from leading to trailing edges
Describe PRF (# of pulse per second)
Rate a which pulses are transmitted.
Measured in pulses per second (Hz)
Measured from leading edge of one to leading edge of next
1 cycle = PRI = 300 cycles for example…= 300 cycles/sec = PRF 300Hz
PRF = 1/PRI
Describe Power output
Peak power = max power transmitted during a pulse
Average power = power averaged over the PRI
Describe pulse shape
Sharp leading and trailing edges = IDEAL
The shorter the pulse width…
the better range resolution. No target overlap..provides 2 distinct target
Longer pulse =
Greater choice of return. Target overlap…results in single returns (appears as 1 target)
Wide pulse =
Greater Max Range
Narrow pulse =
better range resolution
Which Pulse charac. is responsible for Max range?
Power. And to a leaser extent PW…Why? because a shorter PW allows more time to listen for a returning signal from a further distance to get back to the receiver.
Which Pulse charac. is responsible for resolution?
Pulse Width (PW)
Which Pulse charac. is responsible for Range accuracy?
Pulse Shape. And we are looking for a sharp leading edge (for an accurate timing start)
If you wanted to get very accurate ranging & target resolution, what charac. would you ensure?
Pulse shape (Sharp leading and trealing edge) & Narrow PW
If you wanted to increase your max range, but still wanted good target resolution, and couldn’t increase power, what else would you change?
That is beyond our control…
WHAT is the effect of Varying Characteristics?
PRF/PW/Peak Power/Avg Power/ Max range
