A new sampling path for DCIM to capturing the contribution of the branch point

A new sampling path of discrete complex image method (DCIM) is proposed to capture the information of the branch point accurately. The new path comprises of three segments. All these segments are very close to the branch point and the second segment will go through it directly. Along this path the information of the branch point can be captured very accurately. In the situation when the lateral wave dominates the far-field region, the DCIM equipped with the new sampling path gives very accurate result, which is verified by numerical experiments.