Distance measuring using passive visual means

A method to measure a distance between an aircraft refueling boom and a receiving aircraft comprising the steps of:

• installing a refueling boom having a boom nozzle, at least one camera and a computer on a refueling aircraft;
• steering said boom nozzle towards a connection with a refueling receptacle of one of a plurality of receiving aircraft;
• simultaneously viewing line-of-sight images of both said boom nozzle and said refueling receptacle with said camera;
• creating a plurality of images of both said boom nozzle and said refueling receptacle with said camera;
• and
• using said computer to calculate a distance between said boom nozzle and said refueling receptacle using said images.

A method to control a refueling procedure between a refueling aircraft and a receiving aircraft, the refueling aircraft having a refueling boom including a boom nozzle, at least one camera and a computer, the method comprising:

• simultaneously viewing line-of-sight images of both the boom nozzle and a refueling receptacle of the receiving aircraft with the camera;
• creating a plurality of images of both the boom nozzle and the refueling receptacle with the camera;
• calculating a distance between the boom nozzle and the refueling receptacle using the images;
• continuously correcting the distance by performance of multiple update calculations as the distance changes over time;
• and
• directing the boom nozzle to the refueling receptacle using the calculated distance.

A refueling system, comprising:

• a refueling boom supported from a refueling aircraft, the refueling boom having a boom nozzle;
• a receiving aircraft refueling receptacle operably connectable with the boom nozzle;
• a camera installed on the refueling aircraft;
• a computer in communication with both the camera and the refueling boom;
• a camera orientation operably providing both a boom nozzle line-of-sight image and a refueling receptacle line-of-sight image;
• a plurality of digital images of both said boom nozzle line-of-sight image and said refueling receptacle line-of-sight image operably formed by the camera;
• and
• a calculated distance between the boom nozzle and the refueling receptacle extrapolated by the computer from the digital images;
• wherein in an automatic mode the computer is operable to fly the refueling boom to the refueling receptacle using the calculated distance.