Aiming at problem of heading angle error in case of a big dip sharply increase of low-cost electronic compass

error compensation is assumed as from ellipsoid to sphere process. Correction algorithm based on attitude error matrix compensation is studied

electronic compass compensation technique is expanded from planar ellipse compensation to spacial ellipsoid compensation. By means of the least squares method

Newton method

the steepest descent method solve and obtain the final posture error matrix. Experiments can confirm that this method can effectively reduce heading error of electronic compass in the case of big dip

and has advantages of low cost

simple and high reliability.