Models .................................59 Р 4.1 Ellipsoid Geometry .................................59 Р 4.2 Ellipsoid Gravity ................................... 66 Р 4.3 Chapter Summary .................................. 67 Р Problems ........................................68 РChapter 5 . Terrestrial Navigation ........................... 73 Р 5.1 Strap-Down Navigation Systems .......................73 Р 5.2 Local Level Navigation Frame Mechanization Equations ....... 74 Р 5.3 Perturbation Form of Navigation System Error Equations ....... 77 Р 5.4 Navigation System Attitude Error Equations: Psi Formulation ..... 84 Р 5.5 Navigation System Error Equations Using Alternative Р Velocity Error .................................. 84 Р 5.6 Vertical Channel .................................. 88