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In the US, ATC radar and military radar are one and the same - the FAA and the Air Force share the Joint Surveillance System (JSS). So, while the JSS has plenty

In the US, ATC radar and military radar are one and the same - the FAA and the Air Force share the Joint Surveillance System (JSS). So, while the JSS has plenty of limitations (including plenty of areas with no coverage even in the mainland US), it's designed to meet the military objectives of being able to locate even non-cooperating aircraft. The JSS is a descendant of the SAGE system developed during the Cold War to detect soviet aircraft. It has a reduced equipment footprint, but this is generally due to improving radar technology, coverage is similar and the backend data processing systems are much more advanced. The majority of radar sites belong to and are maintained by FAA but report directly to the Air Force air combat system.

ufmace 7y ago
Well that's interesting. How does that tie in to the story's reported change though? I suppose ATCs might be willing to rely solely on aircraft-reported location and speed, but I kind of doubt the USAF would. If they share the same systems, I suppose no equipment would actually change or be decommissioned.
- jcrawfordor 7y ago
  I think that the article's implication that radar is being 'replaced' refers only to the daily work of controllers, not to the technical system. Both the FAA and the Air Force have strong motives to keep the primary radar system, and it would take many years to decommission it even if they wanted to - but near-100% availability of ADS-B does mean that controllers will use it as their primary source of data, instead of relying on the radar returns which even in areas with good coverage can sometimes come in and out and generally be finnicky. Consider that controllers currently rely primarily on secondary radar, which while more difficult to spoof than ADS-B is still quite subject to malicious manipulation. They are well aware that a primary radar return with no corresponding secondary radar information is something to sort out, and this won't change with a switch to ADS-B.
  - briandear 7y ago
    Nobody is even suggesting eliminating radar. ADS-B is primarily for aircraft identification, not terminal area location information. A side effect is that it helps with airborne traffic information for airplanes without radar or TCAS.
jessaustin 7y ago
Is there any other entity that operates these sorts of radomes? On a regular commute of mine, there is one owned by the federal government that has no sign out front [0], but it's not listed on the JSS page [1]. [0] https://goo.gl/maps/KHTP7vruKvGyqQu66 https://goo.gl/maps/KHTP7vruKvGyqQu66 [1] https://en.wikipedia.org/wiki/Joint_Surveillance_System https://en.wikipedia.org/wiki/Joint_Surveillance_System
- madengr 7y ago
  Is that in MO? There is a similar one near Belton. I believe it is C band radar. The FCC database should have it.
- jcrawfordor 7y ago
  It took a bit of digging... this is an FAA radar, but not JSS. It's a secondary radar reporting to the Kansas City ARTCC, code ZQJN. Essentially, it transmits an 'interrogate' message in response to which aircraft transponders transmit information on the aircraft. This is the system that ADS-B is more or less a direct upgrade from. I'm not sure exactly what equipment is installed there, I found an older report listing an ASR-8 at that location but that system is obsolete and inconsistent with a newer list showing it as a secondary (SECRA) site only.
  - jessaustin 7y ago
    You're very knowledgeable! I've been curious about this for a while. The site and equipment does seem well maintained, so I don't think it has been retired yet.

ufmace 7y ago

Well that's interesting. How does that tie in to the story's reported change though? I suppose ATCs might be willing to rely solely on aircraft-reported location and speed, but I kind of doubt the USAF would. If they share the same systems, I suppose no equipment would actually change or be decommissioned.

jcrawfordor 7y ago
I think that the article's implication that radar is being 'replaced' refers only to the daily work of controllers, not to the technical system. Both the FAA and the Air Force have strong motives to keep the primary radar system, and it would take many years to decommission it even if they wanted to - but near-100% availability of ADS-B does mean that controllers will use it as their primary source of data, instead of relying on the radar returns which even in areas with good coverage can sometimes come in and out and generally be finnicky. Consider that controllers currently rely primarily on secondary radar, which while more difficult to spoof than ADS-B is still quite subject to malicious manipulation. They are well aware that a primary radar return with no corresponding secondary radar information is something to sort out, and this won't change with a switch to ADS-B.
- briandear 7y ago
  Nobody is even suggesting eliminating radar. ADS-B is primarily for aircraft identification, not terminal area location information. A side effect is that it helps with airborne traffic information for airplanes without radar or TCAS.

jessaustin 7y ago

Is there any other entity that operates these sorts of radomes? On a regular commute of mine, there is one owned by the federal government that has no sign out front [0], but it's not listed on the JSS page [1]. [0] https://goo.gl/maps/KHTP7vruKvGyqQu66 https://goo.gl/maps/KHTP7vruKvGyqQu66 [1] https://en.wikipedia.org/wiki/Joint_Surveillance_System https://en.wikipedia.org/wiki/Joint_Surveillance_System

madengr 7y ago
Is that in MO? There is a similar one near Belton. I believe it is C band radar. The FCC database should have it.
jcrawfordor 7y ago
It took a bit of digging... this is an FAA radar, but not JSS. It's a secondary radar reporting to the Kansas City ARTCC, code ZQJN. Essentially, it transmits an 'interrogate' message in response to which aircraft transponders transmit information on the aircraft. This is the system that ADS-B is more or less a direct upgrade from. I'm not sure exactly what equipment is installed there, I found an older report listing an ASR-8 at that location but that system is obsolete and inconsistent with a newer list showing it as a secondary (SECRA) site only.
- jessaustin 7y ago
  You're very knowledgeable! I've been curious about this for a while. The site and equipment does seem well maintained, so I don't think it has been retired yet.