Attitude Calculation Based on Sequential Correction of Gravity Field and Geomagnetic Field Mingyong Liu, Jiaojiao Guo, Mengfan Wang, Yun Niu and Lu Wang JNWPU, 38 1 (2020) 1-5 Published online: 12 May 2020 DOI: 10.1051/jnwpu/20203810001