What is the identity of "X" type mysterious structures scattered in the American desert?

Once in AmericaStructures of huge arrows were installed on the ground for the guide of the pilot of the airlineApart from that, a mysterious structure in the form of 'X' that can be clearly seen from the sky is installed in the desert area of ​​Arizona. When you examine what a mysterious structure was installed for whom and for whom it has been revealed that it was used for surprising use.

Decades-Old Mystery Put To Rest: Why Are There X's In The Desert?: NPR
http://www.npr.org/2016/10/11/496567104/decades-old-mystery-put-to-rest-why-are-there-xs-in-the-desert

Pes Owen discovered a white structure in the form of a huge "X" while flying above the Arizona desert in Cessna. Mr. Owen, who had never seen such a structure so far, looked up the flight chart (route map), but the information on the mysterious structure was not stated.

The mysterious structure is about 60 feet (about 18 meters) in size and can be clearly confirmed from the sky coupled with a pure white surface.


Mr. Owen who wanted to know what the mysterious structure is, started a survey to attach the identity of the structure together with former colleague Chuck Pennson. Introduction It was two people who doubted the remains of mines and the military radar base, but both proposals ended in the morning swing.


However, Mr. Owen later confirmed that the map of Arizona / Casa Grande area from the Defense Map Agency got 273 "X" characters. Ultimately, the declassified CIA's "A Point in Time: The Corona StoryIt was explained in the film which was made in 1972 that it was founded in the film "CORONA Satellite Project" which was carried out top secretly during the Cold War era.

CORONA (corona) satelliteIs a satellite launched 100 miles from the earth (about 160 kilometers), the purpose of its operation is to shoot spy photos to monitor the Soviet Union and China. It was mentioned in the film that he was monitoring all the airports and nuclear test facilities owned by the Soviet Union and China.


Although it is a CORONA satellite that recorded more than 800,000 photos over a long period of 12 years, it was necessary to regularly adjust the focus etc. in order to photograph clear images. Prepared for the calibration of the camera is a huge X structure that can be confirmed from the sky, the CORONA satellite finished its mission and remains in the state of the time as it is in the desert of the now Arizona where the Cold War ended It is said that it is.