While walking in Discovery Park I discovered this radar dome with FAA notices on its fence. enter image description here

And not far away I cam across this small FAA signed radio antenna and shack. enter image description here

Any idea what these facilities do?

My guess would be the radar is used by Seattle Center and that the small antenna is a marker beacon for southbound approaches to SeaTac.

  • 1
    $\begingroup$ This is one of those questions that gives me the national security creeps. $\endgroup$ Commented Sep 4, 2018 at 3:44
  • $\begingroup$ Does that mean I should take it down? $\endgroup$ Commented Sep 4, 2018 at 3:47
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    $\begingroup$ The antenna does look like a MB antenna and it may be a decommissioned MB for Rwy 14 at BFI. It's about 8 NM from the threshold, but it's pure conjecture on my part. There are no navaids currently showing on any charts in that location. The only thing I could find in that area is the Fort Lawton RCO for Seattle Center (127.05 MHz). $\endgroup$
    – Gerry
    Commented Sep 4, 2018 at 18:27
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    $\begingroup$ "national security" doesn't depend on hiding RADAR sites, which (of course) must transmit to be effective. RADAR is easily detectable by anyone who cares. $\endgroup$
    – guycole
    Commented Sep 4, 2018 at 20:52
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    $\begingroup$ I lived in Seattle for 20+ years, and used to fly R/C gliders near that radome. At that time (early 1980s), the local glider fliers were convinced it was still active; if you flew near it, you were very prone to radio glitches (the kind of thing you'd get from harmonic interference by a high power off-frequency beam). Thirty-five years later, it still appears to be maintained. $\endgroup$
    – Zeiss Ikon
    Commented Sep 14, 2018 at 13:56

3 Answers 3


A collection of earlier radomes in Discovery Park

Seattle’s "golf ball" in Discovery Park was once part of the country’s Nike Hercules air defense system of missiles and radars in the 1950s. While most of the structures have been torn down, this golf ball still stands as a relic of the Cold War.

Discovery Park used to have an array of radars at its peak. It was a Nike Ajax air defense site in 1953 before becoming an Air Force command center for the Nike Hercules system. The remaining radome was built in 1959. It is not currently in use.

Initially assigned a Permanent ID of RP-1 and later a Sage ID of Z-1. Abandoned by the Air Force in 1963 and turned over to the FAA, now known as Fort Lawton FAA Radar Site.

More information:


First picture is the Air Route Surveillance Radar (ARSR-1E) located at Fort Lawton (source 1, source 2).

The second picture is the NOLLA NDB (long overhead wires) along with an outer marker beacon (dual Y-arranged Yagi antennas). These two used to serve the localizer approach into Boeing Field's 13R (now 14R).


The first picture is the Fort Lawton FAA Radar Site, an active high power long range CARSR RADAR providing data for USAF/NORAD Battle Control System-Fixed (BCS-F) operations centers (EADS & WADS) as well as the FAA Seattle ARTCC (ZSE) and adjacent ARTCCs as well as Homeland Security. It operates between 1.2 and 1.4 GHz at a -minimum- peak power of 50000 watts, the fence is standing far away from the transmitting antenna for a reason-it's dangerous.


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