United States Space Surveillance Network
The Network consists of U.S. Army, Navy and Air Force operated, ground-based radars and optical sensors at 25 sites worldwide.
Figure 1: From Wikipedia -https://en.wikipedia.org/wiki/United_States_Space_Surveillance_Network
- Dedicated sensors
- Collateral sensors
- Auxiliary sensors
Former "Space Fence" - Air Force Space Surveillance System (ceased operation in 2013)
"The AN/FPS-133 Air Force Space Surveillance System, colloquially known as the Space Fence, was a U.S. government multistatic radarsystem built to
detect orbital objects passing over America. It is a component of the US space
surveillance network, and according to the US Navy was able to detect basketball sized (29.5 inches (75 cm)) objects at heights up to 30,000 km (15,000 nautical miles.)
The system ceased operation in September 2013. Plans for a new space fence are underway with sites at
the Kwajalein Atoll in the Marshall Islands, along with an option for another radar site in Western
The operation's headquarters were at Dahlgren, Virginia, and radar stations were spread out across the continental United States at roughly the level of the 33rd parallel
There were three transmitter sites in the system:
Figure 1: From Wikipedia - "Part of the master transmitter antenna at Lake
Kickapoo, Texas c.2001."
Space Fence* soon to become operational
*or "new/2nd generation Space Fence"
"The Space Fence is a second-generation space
surveillance system currently being built by the US Air Force in order to track artificial satellites and space debris in Earth orbit ."
"The initial space fence facility will be located at Kwajalein Atoll in
the Marshall Islands, along with an option for another radar site in Western Australia ."
The Space Fence is a S-band (microwave of 2-4 GHz) RADAR array.
Excerpt from second video: "For high interest objects, a micro-fence can be electronically constructed to gather more track data focusing radar resources
specifically on that object".