There is provided a guidance system for allowing an air vehicle to guide a moving object, comprising a Synthetic Aperture Radar located on the air vehicle, and a means of communication for allowing the air vehicle to communicate with the moving object, wherein the Synthetic Aperture Radar is capable of determining the position and orientation of the air vehicle relative to a desired location, and information provided by the Synthetic Aperture Radar is used, via the means of communication, to guide the moving object towards the desired location. A guidance system wherein a seeker is utilised on the moving object is also provided. The invention further provides a method for allowing an air vehicle to guide a moving object towards a desired location comprising the steps of using a Synthetic Aperture Radar to determine the position and/or orientation of the air vehicle relative to a desired location, establishing a communications link for allowing the air vehicle to communicate with the moving object, using the communications link to provide information to the moving object and thereby to guide the moving object towards the desired location. A method wherein a seeker located on the moving object is utilised is also provided. The invention further provides methods for aligning a radar beam with a target in a Synthetic Aperture Radar image.