5 ms·
They are often called "quantum compasses" although they are complete inertial measurement units which have an accelerometer, magnetometer (a compass is a magnet
by pclmulqdq 2y ago
They are often called "quantum compasses" although they are complete inertial measurement units which have an accelerometer, magnetometer (a compass is a magnetometer), and a gyroscope.
The subtle parts of the magnetic field of the Earth shift a lot related to the movement of metal through the mantle. NOAA and the DoD periodically create new maps of the magnetic field, but they have a lot of error and noise.
- bee_rider 2y agoSure, I’m not saying it is a GPS replacement or anything. But, a measurement of absolute position is a fundamentally different thing from trying to figure out a position by integrating from an IMU, right? The latter inevitably accumulates errors. The former should not accumulate error. The measurements might be extremely noisy, but noisy and error accumulating are different from a signal processing point of view.
- roelschroeven 2y ago(I think you meant to say "The former should not accumulate error" instead of the latter.)
- bee_rider 2y agoGood catch, thanks
- pclmulqdq 2y agoThe magnetometer's reference data is so inaccurate for positioning and shifts so much that error will still accumulate. Magnetometers have been used in IMUs for over 50 years. Their shortcomings have little to do with the precision of the instrument.