The Optimal Degree of Gravity Spherical Harmonic Model Calculation for Gravity Disturbance Compensation in Inertial NavigationJunbo TIE, Meiping WU, Juliang Cao, Junxiang Lian, Shaokun Cai and Lin WangMATEC Web Conf., 160 (2018) 07004DOI: https://doi.org/10.1051/matecconf/201816007004