Chapter 10 - Doppler Radar

Question 1

Draw Doppler

Answer 1

Question 2

41. Compare PD and MTI using relative PRFs and their inherent ambiguities with regards to range and velocity measurement.

Answer 2

o PD: Better for high-speed target detection, resolves velocity well, but suffers from range ambiguities.
o MTI: Better for clutter rejection at low speeds, resolves range well, but suffers from velocity ambiguities.

Question 3

42. Which factors apart from target movement will produce a Doppler shift in a PD radar?

Answer 3

• Internal motion
• Platform motion
• Antenna Scan
• Transmitter Instability

Question 4

44. How does a PD radar calculate if a target is incoming or outgoing?

Answer 4

• Doppler Shift Direction:
o Positive Doppler Shift: Incoming target (frequency increases).
o Negative Doppler Shift: Outgoing target (frequency decreases).

Question 5

45. Determine the size and number of range gates required in a PD radar

Answer 5

Rres = ct/2

mur = c/2PRF

no.rg = MUR / Rres

Question 6

46. How does PD radar reject clutter?

Answer 6

o Doppler Filtering: Differentiates between stationary clutter and moving targets based on Doppler frequency shifts.
o Range Gating: Separates signals based on range, isolating moving targets from stationary clutter.