A method of navigating an unmanned ground vehicle within an area, the method comprising: operating a processor for generating, based on scanning output data received from a scanning device, a first map of an area surrounding the UGV comprising a first group of cells the cells characterized by a first size; the method characterized by: operating the processor for generating, based on the scanning output data and simultaneously with the generating of the first map, a second map of the area surrounding the UGV, which is smaller than the first map and comprising a second group of cells, each of the second group of cells characterized by a second size smaller than the first size; the second map at least partly overlaps the first map; wherein cells in the first group of cells and the second group of cells are classified to a class selected from at least two classes, comprising traversable and non-traversable; operating the processor for generating deduced data based on crossing between cells in the first map and second map, the crossing comprising: crossing between one or more cells from the first group of cells that is classified as non-traversable and one or more corresponding cells from the second group of cells, wherein the deduced data is indicative whether a size of a non-traversable area represented by at least one cell from the first group of cells includes an area which is smaller than the size of the at least one cell from the first group of cells; crossing between one or more cells from the second group of cells that is classified as non-traversable and one or more corresponding cells from the first group of cells, wherein the deduced data is indicative whether a size of a non-traversable area represented by the at least one cell from the second group is greater than the size of the at least one cell from the second group; and generating navigation instructions for navigating the UGV while avoiding collision with one or more obstacles associated with the non-traversable area, using the deduced data. operating a processor for generating, based on scanning output data received from a scanning device, a first map of an area surrounding the UGV comprising a first group of cells the cells characterized by a first size; the method characterized by: operating the processor for generating, based on the scanning output data and simultaneously with the generating of the first map, a second map of the area surrounding the UGV, which is smaller than the first map and comprising a second group of cells, each of the second group of cells characterized by a second size smaller than the first size; the second map at least partly overlaps the first map; wherein cells in the first group of cells and the second group of cells are classified to a class selected from at least two classes, comprising traversable and non-traversable; operating the processor for generating, based on the scanning output data and simultaneously with the generating of the first map, a second map of the area surrounding the UGV, which is smaller than the first map and comprising a second group of cells, each of the second group of cells characterized by a second size smaller than the first size; the second map at least partly overlaps the first map; wherein cells in the first group of cells and the second group of cells are classified to a class selected from at least two classes, comprising traversable and non-traversable; operating the processor for generating deduced data based on crossing between cells in the first map and second map, the crossing comprising: crossing between one or more cells from the first group of cells that is classified as non-traversable and one or more corresponding cells from the second group of cells, wherein the deduced data is indicative whether a size of a non-traversable area represented by at least one cell from the first group of cells includes an area which is smaller than the size of the at least one cell from the first group of cells; crossing between one or more cells from the second group of cells that is classified as non-traversable and one or more corresponding cells from the first group of cells, wherein the deduced data is indicative whether a size of a non-traversable area represented by the at least one cell from the second group is greater than the size of the at least one cell from the second group; and generating navigation instructions for navigating the UGV while avoiding collision with one or more obstacles associated with the non-traversable area, using the deduced data. crossing between one or more cells from the first group of cells that is classified as non-traversable and one or more corresponding cells from the second group of cells, wherein the deduced data is indicative whether a size of a non-traversable area represented by at least one cell from the first group of cells includes an area which is smaller than the size of the at least one cell from the first group of cells; crossing between one or more cells from the second group of cells that is classified as non-traversable and one or more corresponding cells from the first group of cells, wherein the deduced data is indicative whether a size of a non-traversable area represented by the at least one cell from the second group is greater than the size of the at least one cell from the second group; and generating navigation instructions for navigating the UGV while avoiding collision with one or more obstacles associated with the non-traversable area, using the deduced data.