Passive coherent radar is a type of multistatic radar in which civilian RF transmissions of opportunity can be used to determine disturbances in the baseline RF environment.

Passive coherent radar is a type of multistatic radar in which civilian RF transmissions of opportunity can be used to determine disturbances in the baseline RF environment.

• A. It uses civilian RF transmissions of opportunity to determine disturbances in the baseline RF environment
• B. It uses military RF transmissions only
• C. It is a monostatic radar
• D. It does not rely on external transmissions

Answer: (A)

Passive coherent radar relies on illuminators of opportunity—external civilian RF signals such as broadcast or cellular transmissions—to observe a scene. The radar receiver exploits these signals, which come from sources separate from the radar itself, to detect changes in the propagation environment caused by objects moving or evolving clutter. This multistatic arrangement means the transmitter and receiver are in different locations, using the civilian transmissions rather than any signal generated by the radar. Because the essence is using those civilian signals to reveal disturbances in the baseline RF environment, that statement is the best description. The other options misrepresent the source of illumination (not limited to military transmissions), the system geometry (not monostatic), or the reliance on external transmissions (it does rely on them).

Passive coherent radar relies on illuminators of opportunity—external civilian RF signals such as broadcast or cellular transmissions—to observe a scene. The radar receiver exploits these signals, which come from sources separate from the radar itself, to detect changes in the propagation environment caused by objects moving or evolving clutter. This multistatic arrangement means the transmitter and receiver are in different locations, using the civilian transmissions rather than any signal generated by the radar. Because the essence is using those civilian signals to reveal disturbances in the baseline RF environment, that statement is the best description. The other options misrepresent the source of illumination (not limited to military transmissions), the system geometry (not monostatic), or the reliance on external transmissions (it does rely on them).