How does inertial navigation system work in polar regions?

Inertial navigation systems (INS) in polar regions operate by utilizing accelerometers and gyroscopes to measure changes in velocity and orientation. These measurements are integrated over time to calculate the position of the device without relying on external signals, which can be scarce in remote polar areas. However, challenges arise due to the Earth's rotation and the unique geometry of polar navigation, necessitating adjustments to account for factors such as magnetic declination and the curvature of the Earth. As a result, periodic updates from external references, like GPS, may be required to maintain accuracy over long durations.