“…A sparse representation formed only by isolated landmarks will in general not fulfil the necessities of an autonomous vehicle, and a more detailed representation will be needed for tasks such as place recognition or path planning. Furthermore, not only is a dense representation of the environment required, but also an algorithm that is able to obtain multi-layered maps, where each layer represents a different property of the environment, such as occupancy, traversability, elevation, etc (Lacroix et al, 2002).…”