Rapid lidar image correlation for ground navigation

A method comprising:

• generating, by at least one processor, a current coarse edge count representation of a current section of an environment based on a current fine grid representation of the current section of the environment, wherein each current coarse pixel in the current coarse edge count representation represents a plurality of current fine pixels from the current fine grid representation, wherein the fine grid representation of the current section of the environment is based on data from a range and attitude sensor capable of generating signals relating to a geographic location of at least one object in a current section of the environment;
• wherein each current coarse pixel within the current coarse edge count representation includes a current edge quantity value that represents the quantity of the plurality of current fine pixels from the current fine grid representation represented by the current coarse pixel that include an edge;
• correlating, by the at least one processor, 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;
• identifying, by the at least one processor, a first subsection of the historical coarse edge count representation that has the highest correlation to the current coarse edge count representation;
• and
• correlating the current fine pixels of the current fine grid representation with a first subsection of the historical fine pixels of the historical fine grid representation that matches the first subsection of the historical coarse edge count representation to identify a geographic location of the range and attitude sensor within the first subsection of the historical fine pixels of the historical fine grid representation.

A system comprising:

• a LIDAR sensor configured to generate signals relating to a geographic location of at least one object in a current section of an environment relative to the system;
• a processor coupled to the LIDAR sensor and configured to calculate a navigation solution based on signals received from the LIDAR sensor;
• wherein the processor is configured to generate a current fine grid representation of the current section of the environment based on the signals relating to the geographic location of the at least one object in the current section of the environment generated by the LIDAR sensor, wherein the current fine grid representation includes a plurality of current fine grid pixels, wherein each current fine grid representation pixel includes a value representing a height of an object in a separate current fine edge pixel area of the current section of the environment;
• wherein the processor is configured to generate a current fine edge representation of the current section of the environment by performing edge detection between adjacent current fine grid pixels in the current fine grid representation of the current section;
• wherein the current fine edge representation includes a plurality of current fine edge pixels, wherein each current fine edge pixel represents the respective separate current fine edge pixel area of the current section of the environment, wherein each current fine edge pixel indicates whether an edge is present in the respective separate current fine edge pixel area associated with the respective current fine edge pixel;
• wherein the processor is configured to generate a current coarse edge count representation of the current section of the environment based on the current fine edge representation 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 separate current coarse area of the current section of the environment, wherein the separate current coarse area is larger than the separate current fine edge pixel area and contains a plurality of separate current fine edge pixel 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;
• 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;
• and
• wherein the processor is configured to correlate the current fine edge pixels of the current fine edge representation with a first subsection of the historical fine pixels of the historical fine grid representation that matches the first subsection of the historical coarse edge count representation to identify a geographic location of the LIDAR sensor within the first subsection of the historical fine pixels of the historical fine grid representation.