Why does the GPS lose lock when subject to high G forces?
The GPS uses very sensitive timing oscillation based on a crystal. Under high G forces this crystal becomes out of tune, and ‘time’ fails. This causes the GPS to fail to be able to calculate properly and the lock is lost. Most GPS units support up to 4 Gs before the crystal goes out of tune. Depending on how you mount the unit it may support up to 20 G force for short periods without losing lock. Subjecting your unit to up to 20 Gs does not damage it permanently, but will often lose lock. Lock should recover once the unit is below 4 Gs for a while.
