1. A system comprising: a range and attitude sensor configured to generate signals relating to a location of at least one object in a current section of an environment relative to the system; at least one processor coupled to the range and attitude sensor and configured to calculate a navigation solution based on signals received from the range and attitude sensor; wherein the at least one processor is configured to generate a current coarse edge count representation of the current section of an environment based on a current fine edge representation of the current section of the environment; wherein the current fine edge representation is based on the signals received from the sensor and includes a plurality of current fine edge pixels, wherein each current fine edge pixel represents a first area of the current section of the environment, wherein each current fine edge pixel indicates whether an edge is present in the first area of the current section of the environment; wherein the current coarse edge count representation includes a plurality of current coarse pixels, wherein each current coarse pixel represents a second area of the current section of the environment, wherein the second area is larger than the each first area and contains a plurality of first areas; wherein each current coarse pixel in the current coarse edge count representation corresponds to a plurality of current fine grid pixels in a current fine grid representation; wherein each current coarse pixel in the current coarse edge count representation includes a current edge quantity value that indicates the quantity of the plurality of current fine edge pixels from the current fine edge representation corresponding to the current coarse pixel that include an edge; wherein the processor is configured to correlate the current edge quantity values of the current coarse pixels of the current coarse edge count representation with historical edge quantity values of historical coarse pixels of a historical coarse edge count representation of the environment, wherein each historical coarse pixel in the historical coarse edge count representation corresponds to a plurality of historical fine pixels in a historical fine grid representation of the environment; and wherein the processor is configured to identify a first subsection of the historical coarse edge count representation that has the highest correlation to the current coarse edge count representation.