A navigation system for a dynamic platform, the navigation system comprising: an inertial navigation system, INS, unit comprising: a three-axis accelerometer attached to the dynamic platform for measuring, in real-time, linear accelerations of the dynamic platform along three orthogonal spatial axes; a three-axis gyroscope attached to the dynamic platform for measuring, in real-time, angular velocities of the dynamic platform along three orthogonal angular axes; and a processor communicatively coupled to the accelerometer and the gyroscope, the processor configured to determine in real-time, using dead reckoning, initial estimates of current positions and initial estimates of current orientations of the dynamic platform based on a previous position and a previous orientation of the dynamic platform, and the linear accelerations and angular velocities of the dynamic platform; an exteroceptive sensor attached to the dynamic platform and configured to acquire, in real-time, sequential images of an environment in which the dynamic platform is traveling; a simultaneous localization and mapping, SLAM, unit coupled to the exteroceptive sensor, the SLAM unit comprising a local sub-map tracker configured to estimate, in real-time, visual odometer, VO, pose changes of the dynamic platform using the sequential images, each VO pose change including a change of position and a change of orientation of the dynamic platform; and a sensor fusion engine communicatively coupled to the INS unit and the SLAM unit, the sensor fusion engine configured to determine estimates of current positions and estimates of current orientations of the dynamic platform based at least in part on the initial estimates of current positions and the initial estimates of current orientations determined by the INS unit, and the VO pose changes estimated by the local sub-map tracker; wherein the processor of the INS unit is further configured to update the initial estimates of current positions and the initial estimates of current orientations of the dynamic platform to obtain absolute current positions and absolute current orientations of the dynamic platform using the estimates of current positions and the estimates of current orientations of the dynamic platform determined by the sensor fusion engine. an inertial navigation system, INS, unit comprising: a three-axis accelerometer attached to the dynamic platform for measuring, in real-time, linear accelerations of the dynamic platform along three orthogonal spatial axes; a three-axis gyroscope attached to the dynamic platform for measuring, in real-time, angular velocities of the dynamic platform along three orthogonal angular axes; and a processor communicatively coupled to the accelerometer and the gyroscope, the processor configured to determine in real-time, using dead reckoning, initial estimates of current positions and initial estimates of current orientations of the dynamic platform based on a previous position and a previous orientation of the dynamic platform, and the linear accelerations and angular velocities of the dynamic platform; a three-axis accelerometer attached to the dynamic platform for measuring, in real-time, linear accelerations of the dynamic platform along three orthogonal spatial axes; a three-axis gyroscope attached to the dynamic platform for measuring, in real-time, angular velocities of the dynamic platform along three orthogonal angular axes; and a processor communicatively coupled to the accelerometer and the gyroscope, the processor configured to determine in real-time, using dead reckoning, initial estimates of current positions and initial estimates of current orientations of the dynamic platform based on a previous position and a previous orientation of the dynamic platform, and the linear accelerations and angular velocities of the dynamic platform; an exteroceptive sensor attached to the dynamic platform and configured to acquire, in real-time, sequential images of an environment in which the dynamic platform is traveling; a simultaneous localization and mapping, SLAM, unit coupled to the exteroceptive sensor, the SLAM unit comprising a local sub-map tracker configured to estimate, in real-time, visual odometer, VO, pose changes of the dynamic platform using the sequential images, each VO pose change including a change of position and a change of orientation of the dynamic platform; and a sensor fusion engine communicatively coupled to the INS unit and the SLAM unit, the sensor fusion engine configured to determine estimates of current positions and estimates of current orientations of the dynamic platform based at least in part on the initial estimates of current positions and the initial estimates of current orientations determined by the INS unit, and the VO pose changes estimated by the local sub-map tracker; wherein the processor of the INS unit is further configured to update the initial estimates of current positions and the initial estimates of current orientations of the dynamic platform to obtain absolute current positions and absolute current orientations of the dynamic platform using the estimates of current positions and the estimates of current orientations of the dynamic platform determined by the sensor fusion engine.