Thanks to the high performance of the spaceborne GPS receiver and the availability of precise IGS orbit and clock products,zero-difference kinematic precise orbit determination(POD) has been turned out to be a new effective method in orbit determination for the LEO satellites.Zero-difference kinematic POD,which is based on the GPS measurements only from the spaceborne GPS receiver,does not depend on the force models and orbit design.From this point of view,kinematic POD is suitable for the Earth observation...