Yes, you can buy an IMU as a single IC for less than $5[1]. Otherwise your smartphone probably already have all the required sensors.
Of course, those have significantly less performance than the one you put in an
airliner or ballistic missile.
As you mention yourself, its a question of good enough. You need to be a lot more accuracy to hit a city after a twenty minute sub-orbital coast, than to find the nearby trench.
And yes, computer vision is used to correct for drift.
Of course, those have significantly less performance than the one you put in an airliner or ballistic missile.
As you mention yourself, its a question of good enough. You need to be a lot more accuracy to hit a city after a twenty minute sub-orbital coast, than to find the nearby trench. And yes, computer vision is used to correct for drift.
[1]: IMU's on DigiKey: https://www.digikey.com/en/products/filter/motion-sensors/im...