Abstract: For underground pipeline trenchless detection, a new method is proposed that employs EZ-COMPASS-3 to detect the anglular information of discrete points on the pipeline, and reconstruct the spatial trajectory of the pipeline with a newly developed reconstruction algorithm. EZ-COMPASS-3 is a kind of electronic compass, consisting of a 3-dimensional magnetometer and two tilt compensated sensors. Hard iron compensation and tilt compensation should be included to enhance measure accuracy. The corresponding compensation theory is described. Theoretical analysis and testing of the errors show effectiveness of the proposed method.

Key words: corresponding compensation theory, error analysis, trenchless underground pipeline detection