The INS is described as which of the following?

• A. Inaccurate and jam-prone
• B. Requires ground-based support
• C. Treats signals as external references
• D. Accurate, non-jammable, self-contained, non-radiating

Answer: (D)

An Inertial Navigation System relies on onboard sensors to determine position, velocity, and attitude without using external navigation aids. It measures rotation with gyros and linear acceleration with accelerometers, then integrates those signals to track movement. Because nothing external is referenced and no signals are transmitted from the system, it is self-contained and non-radiating, and it isn’t susceptible to radio jamming in the way radio-based navaids are. With proper alignment and calibration, it provides accurate navigation over short periods; however, errors drift over time without external updates. This combination—high short-term accuracy, immunity to jamming, and being self-contained and non-radiating—explains why the description fits best.