Abstract: The progressive multi-channel correlation (PMCC) method is the primary method for locating the infrasound source. However, this method introduces errors due to ignoring the altitude difference between array elements. In this paper, the time delay estimation algorithm based on the generalized cross-correlation is analyzed; the localization method based on incident angles of the plane wave with time delay is discussed; the source of errors of the progressive multi-channel correlation method is studied, and it is determined that the errors of the infrasound source localization come from ignoring the altitude difference between array elements. Based on the least squares method, the method of calculating the incident angles of the infrasound wave without considering element height is derived. The error simulation experiment of the triangular quaternion array with element height difference is carried out. The maximum localization errors in all directions under the condition of ignoring the altitude difference between array elements are 4°. The relationship between the maximum element altitude difference and the incident angle computation error is linear. The influence of the incident angle computation error on the main parameters and subsequent localization is discussed.