“…Numerous algorithms of Helmert transformation have been presented. On the one hand, the algorithms can be classified to a numerical iterative algorithm, e.g., El-Habiby et al (2009), Zeng and Yi (2011), Paláncz et al 2013, Zeng et al (2016, etc., and an analytical algorithm, e.g., Grafarend and Awange (2003), Shen et al (2006a, b), Zeng (2015), etc. For the numerical iterative algorithm, initial values of transformation parameters are usually required.…”