I'm working on some of the math for rocket attitude determination
based only on magnetometer data (and location on earth). I was hoping
to make some statements in hopes that some of the gurus in this area
might be able to verify (or correct) these statements.

(note: a single vector includes both positive and negative directions)

If you have a single axis magnetometer parallel to the lengthwise axis (z-axis) of the rocket, with or without a spin rate, you have a cone of possible orientation vectors based on the magnetometer data.

With a 2-axis magnetometer (x and z axis), you can equate the possible attitude vectors of a non-spinning rocket down to a function of x-axis sensor orientation vectors (which is still an infinite number and pretty much useless in itself). If the rocket is spinning, you can reduce the possible attitude orientation vectors down to 4 based on the magnitude of the deviation during a revolution of the x-axis magnetometer data ... ?

Lastly, with a 3-axis magnetometer rocket, you could determine the exact attitude vector of the rocket regardless of spin...?

Any verification, corrections, or suggestions to my understanding is greatly appreciated.

Thanks! Dave

(note: a single vector includes both positive and negative directions)

If you have a single axis magnetometer parallel to the lengthwise axis (z-axis) of the rocket, with or without a spin rate, you have a cone of possible orientation vectors based on the magnetometer data.

With a 2-axis magnetometer (x and z axis), you can equate the possible attitude vectors of a non-spinning rocket down to a function of x-axis sensor orientation vectors (which is still an infinite number and pretty much useless in itself). If the rocket is spinning, you can reduce the possible attitude orientation vectors down to 4 based on the magnitude of the deviation during a revolution of the x-axis magnetometer data ... ?

Lastly, with a 3-axis magnetometer rocket, you could determine the exact attitude vector of the rocket regardless of spin...?

Any verification, corrections, or suggestions to my understanding is greatly appreciated.

Thanks! Dave