Tkachenko Mikhail Gelievich RussiaМехико Autonomous University of Mexico, Doctor Atl 37, Santa María la Rivera, 06400 Cuauhtémoc, D.F., Mexico Professor of the Chair of MathematicsDoctor of Sciencesmich@xanum.uam.mx Author's articles Analytical Solution of Linear Differential Error Equations of Strapdown Inertial Navigation System, Functioning in the Normal Geographic Reference Frame, for the Case of an Object, Following the Geographical Equator