US Patent 8705022 Navigation system using both GPS and laser reference

A machine control system uses a laser system and global navigation satellite system to determine the position of the machine. The laser system has a laser detector positioned in a known and fixed relationship with the nominal phase center of a global navigation satellite antenna. The laser detector receives laser light transmitted from a laser transmitter. The outputs of the laser system and the global navigation satellite system are used together to determine the position of the transmitter prior to being used to determine the position of the machine.