For jammer access to be effective, the jammer must be in line of sight to the target footprint.

• A. In line of sight/footprint
• B. Line of sight is optional
• C. Power alone suffices
• D. Only if physically close

Answer: (A)

Interference works best when the jammer has a direct, unobstructed path to the area where the target receiver is located. With line of sight to the footprint, the RF energy travels with minimal blockage, so the interfering signal reaches the receiver with enough strength to disrupt its operation. Any obstruction—terrain, buildings, or other structures—attenuates, diffracts, or blocks the signal, drastically reducing the jammer’s effectiveness. Simply having a lot of power doesn’t help if the path is blocked; being close but shielded still fails because the energy can’t couple efficiently into the target receiver. So the most effective condition is a clear line of sight to the footprint.