“…For example, Keating and Pilkington (2004) apply the Euler equation to analytic signal of the potential field to estimate source location and SI simultaneously. Salem et al (2008) develop a linear equation without the parameter SI by applying tilt angle, which is known as Tilt-Euler method and followed by many researches (Ma, 2013(Ma, , 2014Alamdar et al, 2014;Guo et al, 2014Guo et al, , 2020Wang et al, 2019). In our previous studies, we also suggest an improved Euler method to avoid the parameter SI (Huang et al, 2019) based on high-order derivatives.…”