Which inertial systems can provide backup position information?

Which inertial systems can provide backup position information?

• A. INS or IRS
• B. GPS and GLONASS
• C. VOR and DME
• D. ADF and DME

Answer: (A)

Inertial systems rely on onboard accelerometers and gyroscopes to track motion and compute position, velocity, and attitude from a known starting point. Because they don’t depend on external navigation signals, they can keep providing position information even if GPS or other external aids fail, making them suitable as a backup source. However, they drift over time due to sensor biases and accumulated errors, so they’re best used for short-term backup with updates from other sources when available. The other options rely on external signals or ground-based beacons and do not provide true inertial navigation data: satellite systems require signals from space, VOR/DME gives position relative to stations, and ADF/DME provide bearing and distance rather than an autonomous inertial position.

Inertial systems rely on onboard accelerometers and gyroscopes to track motion and compute position, velocity, and attitude from a known starting point. Because they don’t depend on external navigation signals, they can keep providing position information even if GPS or other external aids fail, making them suitable as a backup source. However, they drift over time due to sensor biases and accumulated errors, so they’re best used for short-term backup with updates from other sources when available. The other options rely on external signals or ground-based beacons and do not provide true inertial navigation data: satellite systems require signals from space, VOR/DME gives position relative to stations, and ADF/DME provide bearing and distance rather than an autonomous inertial position.