1. A system for determining heading that is mountable on a traveling vehicle, the system comprising: an image system that captures multiple distinctive features in an area of interest at a first point in time and at a second point of time during traveling of the traveling vehicle, matches the multiple distinctive features captured at the first point of time and the second point of time, and determines a first unit-vector associated with a given matched distinctive feature based on the first point in time and a second unit-vector associated with the given matched distinctive feature associated with the second point in time for each of the multiple matched distinctive features; a global positioning system (GPS) that determines a translation vector based on carrier phase information captured from the first point in time to the second point in time; and a coupled processor that minimizes the error in an epipolar equation for each of the multiple matched distinctive features based on the respective first and second unit-vectors and the translation vector to determine a corrected heading, wherein the epipolar equation comprises data characterizing a distinctive feature captured at the first point in time and a distinctive feature captured at the second point in time.