The possibility of using the analytical model of a trajectory of movement of the locomotive in the synthesis of its tight coupling inertial-satellite navigation system. In view of the fact that currently the integration algorithms of strapdown iner- tial navigation systems and satellite navigation systems are formed in most cases either on the basis of the differential model of motion of the locomotive, either on the basis of error equations of inertial navigation systems, information about the trajectory of the locomotive is very limited in accuracy, which leads to significant errors in the inertial-satellite systems in close integration, or the rapid divergence of the filtering process in case of satellite communications. However, as the loco- motives are moving on a known high-precision spatial trajectories, it is proposed to use a spatial model of the way that will greatly simplify the solution of a navi- gational task. It is shown that application of this model reduces the dimension of the estimated vector of the navigation parameters, reducing the computational cost, and allows you to fundamentally solve the problem a posteriori estimates of the motion parameters of auxiliary gauges in case of satellite communications. These study precision indicates the possibility of effective use of the proposed approach and the implementation of the claimed benefits.