April 8, 2015

Torus: the antenna to significantly increase satellite interception

(Updated: November 24, 2015)

At three satellite facilities, in Britain, Cyprus and New Zealand, there's a special antenna that allows NSA's partner agencies a significant increase in their capability to collect satellite communications.

This antenna is called Torus, and while conventional parabolic dish antennas can only view one satellite at a time, one single Torus antenna is able to receive the signals from up to 35 communications satellites.

These rare and expensive Torus antennas are used by some television networks, but a close look at photos of the Five Eyes satellite stations has now revealed the locations where Torus antennas are also used for gathering signals intelligence.

A General Dynamics Satcom Technologies Torus antenna
with the array of receiver heads clearly visible

The Torus antenna is rectangular, instead of circular like the conventional satellite dishes. Its quasi-parabolic shape is actually a section of a geometrical shape called torus, which it gave its name. Where a conventional satellite antenna only has one receiving head, called a Low-Noise Block (LNB) downconverter, a Torus antenna has many of them, placed in an array.

How one Torus antenna (brand name Simulsat) is able
to receive the signals of up to 35 satellites
(Source: Evertz.com - Click to enlarge)

With a focal arc instead of a single focus point, the Torus antenna can pick up the signals from a range of satellites which are in a GeoStationary Orbit (GSO), a fixed position above the equator. This is the case for most of the more than 100 communications satellites. Because a Torus antenna has to be aligned with the position of multiple satellites, it has to be adjusted to a specific position and therefore cannot be turned or spin around like circular satellite dishes.

Satellite collection

The usage of Torus antennas for signals intelligence first became clear from a slide that was part of a 2011 presentation for the annual Five Eyes conference. It was published in May 2014 in Glenn Greenwald's book No Place To Hide.

The slide is titled "New Collection Posture" and contains a diagram showing the various steps in the process of satellite collection. Greenwald saw this as evidence that NSA wants to "Collect it All", although the diagram clearly shows this refers to just one particular stage:

(The full presentation for this slide)

For the first step of this process it's said that "Torus increases physical access" - a clear description of the fact that one such antenna can receive the signals from many satellites. With one satellite having between 24 and 32 transponders to relay a signal, one Torus antenna, under the right circumstances, could in theory receive nearly 1,000 communications channels simultaneously.

This doesn't necessarily means that with Torus antennas, the Five Eyes agencies are now "collecting everything". The new antenna allows them access to much more satellites, but in the next stage (dubbed "Know it All") they look for and pick out the channels that have the best chances for useful information.

More access also means the need for more capacity to process these incoming signals, because they have to be converted, demodulated and demultiplexed before something can be done with them. And for internet communications, also more XKEYSCORE (XKS) servers would be needed for buffering, so analysts can sort out data of interest.

Torus antennas are useful to "increase the haystack", which doesn't mean that the whole haystack is stored - only those tufts that are likely to contain "needles".

Torus interception antennas

Now knowing what to look for, it was quite easy to "spy back" on the satellite intercept stations through the aerial images of Google Maps. By doing so, we can recognize Torus antennas in Britain, Cyprus and New Zealand.

Waihopai, New Zealand

Most information about the use of a Torus antenna for signals intelligence is available for the one at the Waihopai satellite intercept station in New Zealand, which is codenamed IRONSAND.

According to an article that was originally published in The Marlborough Express in July 2007, the Torus at Waihopai was built the month before and was expected to be operational later that year. Then GCSB director Bruce Ferguson said that this new dish would enable satellites to be tracked more efficiently, and with a cost of under 1 million dollars, it was very good value for money, he said.

The Waihopai station in 2012, with the Torus antenna at the far left
(Photo: Gilbert van Reenen/Vital Images - Click to enlarge)

The new Torus antenna joined the existing satellite dishes, the first of which was built in 1989, and the second in 1998. These dishes are covered by domes, which make them look like giant golf balls. According to the GCSB director this was to ward off the weather, but it is generally considered that it is actually to prevent seeing which direction the dishes face.

The Torus didn't get such a covering, maybe because it only has limited ability to manoeuvre on a fixed pad. But had the Torus antenna been covered like the old dishes, we wouldn't have known about this new and increased satellite interception capability.

The GCSB satellite station Waihopai, before (2005) and
after (2008) the Torus antenna was installed

The Torus at Waihopai is also mentioned in a recently disclosed GCSB presentation from April 2010, which says: "TORUS now enabling an increase of COMSAT/FORNSAT collection". This sounds like this antenna became operational not long before, although it was already installed in 2007. Maybe it took a few years before the necessary processing capacity became fully functional.

Bude, United Kingdom

A second Torus antenna used for satellite interception is at GCHQ Bude, in the west of Cornwall, in the United Kingdom. Bude, codenamed CARBOY, is a large station where GCHQ and NSA cooperate in the interception of both satellite and submarine cable communications.

Here, satellite interception started in the late 1960s with two giant dishes with a diameter of 27 meters. Nowadays there are 21 satellite antennas of various sizes that can cover all the main frequency bands and seem generally orientated towards the INTELSAT, Intersputnik and INMARSAT communication satellites.

The Torus antenna at GCHQ Bude must have been installed somewhere between January 2011 and June 2013: on the current Google Maps image, which is from December 30, 2010, the Torus antenna isn't yet present, but in the picture below, which is from June 23, 2013, the distinctively shaped antenna is clearly visible:

Satellite dishes at GCHQ Bude in Cornwall, with the Torus
antenna just right of the big radome in the center
(Photo: Reuters/Kieran Doherty - Click to enlarge)

Ayios Nikolaos, Cyprus

A third Torus antenna is installed at the GCHQ listening station Ayios Nikolaos, which is part of the British Sovereign Base Area (SBA) of Dhekelia in Cyprus, where British signals intelligence has already been present since the late 1940s.

This listening station is codenamed SOUNDER and is part of the Five Eyes satellite interception network that became known as ECHELON. A Google Maps satellite photo shows that there are several large and small satellite dishes, including one that can be recognized as a Torus antenna:

Satellite dishes at GCHQ Ayios Nikolaos in Cyprus with
the one at the left recognizable as a Torus antenna
(Photo: Google Maps - Click to enlarge)

This satellite image is from April 12, 2014, but because for this location no earlier images are available, it's not possible to say in which year this Torus antenna was installed. This makes that for now, the oldest reference to a Torus antenna used for signals intelligence is for Waihopai in New Zealand (2007).

As a reader noticed in a comment below, images from Google Earth show that the Torus antenna at Ayios Nikolaos must have been built somewhere between May 2008 and April 2011, according to the images available for those dates.

So for signals intelligence, Torus antennas were subsequently set up in Waihopai (2007), in Ayios Nikolaos (between 2008 and 2011) and in Bude (between 2011 and 2013).

A GCHQ document from July 2010 mentions Torus as one of the then current projects "which provide new capabilities and may reduce support costs".

According to a report (pdf) from the Nautilus Institute about Torus antennas from May 28, 2015, a Torus was also installed at Menwith Hill Station late 2011, this time underneath a slightly 'squashed' radome. Another one was installed in 2012 at the GCHQ satellite station near Seeb in Oman, which is codenamed SNICK. Finally, in 2008, a Torus antenna was set up at the Pine Gap station in Australia, which also got a satellite intercept function in the early 2000s.

No Torus dishes were visible at the other major satellite stations of the Five Eyes countries, like Yakima and Sugar Grove in the US, Menwith Hill in the UK, Misawa in Japan, and Geraldton in Australia. Torus antennas can also not be seen in aerial photos of the satellite intercept facilities in allied countries like The Netherlands, Denmark, Germany, and Austria.


The Torus antenna was developed in 1973 by COMSAT Laboratories in Clarksburg, Maryland, where it operated an experimental installation that communicated with Intelsat satellites.

The original version of the Torus antenna was able to receive the signals of up to 7 satellites simultaneously and costed 1,1 million US dollars. At that time, the price of a conventional dish, that was much larger than those used nowadays, was around 800,000 dollars.

Probably the first experimental Torus antenna of Comsat,
here being disassembled in August 2007
(Photo: Dennis Boiter/Comara.org - Click to enlarge)

In 1979, COMSAT applied for the Federal Communications Commission (FCC) to build three Torus antennas for commercial use: in Etam (West Virginia), Andover (Maine) and Jamesburg (California). Each of them had to communicate simultaneously with three American domestic satellites which were in a geostationary orbit at 4° degrees apart from eachother.

After the presentation of the first commercial Torus antenna in 1981, the system didn't become very popular, apparently because the efficiency of this antenna type was less than the parabolic satellite dishes and also had increased sidelobe levels. General Dynamics was apparently able to reduce these effects by the offset design of its custom made antennas.


The largest and custom made Torus antennas appear to be manufactured by General Dynamics Satcom Technologies. Smaller, standard Torus antennas are available from General Dynamics' subsidiary Antenna Technology Communications Inc (ATCi), which produces three types under the brand name Simulsat. The width of these dishes is between 8 and 13 meters.

Reportedly there are only about 20 Torus antennas in the world, but it's not clear whether this number is only about the largest ones made by GD Satcom Technologies, or that it also includes that smaller dishes from ATCi. Main customers are the US federal government and television stations that feed their cable networks with a large number of satellite channels.

Simulsat antenna at the Microsoft campus in Silicon Valley

Television networks

An example of a Torus used by television networks is the American sports broadcaster ESPN, which had a 24-meter Torus antenna installed at its headquarters in Bristol, Connecticut, in 2007. DIRECTV has three Torus dishes, including one at its Los Angeles Broadcast Center (LABC), which receives signals from 32 satellites.

It's not known what the price of a Torus antenna is, but it comes probably near 1 million dollars. This can be worth it as one single Torus eliminates the need to install multiple conventional parabolic dishes, that can cost up to several hundred thousand dollars each.

After this article had been published, a number of other Torus-antennas were found by Cryptome, @sigwinch and other people. Most of them are at the dish farms of television networks and commercial satellite companies. Until now, 17 additional Torus antennas can be seen at:

- CIA headquarters (present already in 2000)
- Schriever Air Force Base in Colorado
- An Intelsat ground station near Napa, California (2)
- An Intelsat ground station in Nuevo, California
- An Intelsat ground station near Atlanta, Georgia
- An RRsat America ground station near Hawley, Pennsylvania
- An Intelsat dish farm in Long Beach, California
- An Echostar satellite downlink facility in Chandler, Arizona
- The Intelsat Teleport near Castle Rock, Colorado
- An Echostar Broadcast Center in Cheyenne, Wyoming
- A satellite station near Lake Pochung, New Jersey
- A satellite ground station in Vernon county, New Jersey
- The HBO Communication Center in Hauppage, New York
- The roof of HBO Studio Productions in New York City (2)
- The Inmarsat access station in Nemea, Greece

Links and sources
- Nautilus.org: Expanded Communications Satellite Surveillance and Intelligence Activities Utilising Multi-beam Antenna Systems (pdf)
- Stuff.co.nz: Snowden Files: Inside Waihopai Domes
- Business sheet: General Dynamics SATCOM Technologies Business Overview (pdf)
- Product sheet: General Dynamics 7.0 Meter Torus (pdf)


Anonymous said...

Informative and useful. Thanks.

I can imagine reconfigurable Torus aerials (with "drivers" to deform the surface). Wouldn't surprise me if additive manufacturing, open source etc. make it easier to acquire this capability. If that happens we'll all need to be more aware of eavesdroppers.

Interesting that they chose not to hide it in a golf ball. Presumably budget constraints and a "story" that the enemy would know what you ordered, despite a golf ball.

OSS said...

There's on in Chandler, Arizona as well. I think it's the Applied Satellite Technology Systems network TV downlink farm.

OSS said...

It's actually Echostar.


Anonymous said...

The Torus antenna at GCHQ Ayios Nikolaos was built at some point between May 2008 and April 2011 - There's imagery from these times available in Google Earth (the desktop program version).

Anonymous said...

It's not strictly true that a dish can receive only one satellite. I have a DISH network dish for tv that can get 2 satellites. there are models that can receive 3 or more satellites.

Anonymous said...

The Russian intel also uses a huge Torus Antenna near Moscow. It appears to be much bigger than the ones shown here. You can find the SigInt site at the following location: 55°22'8"N 37°28'45"E

Pictures of the site (which already operated in Soviet times, but has been heavily expanded over the past few years) can be found here: http://www.panoramio.com/photo/36716056

Anonymous said...

Btw it would be quite interesting to find out the manufacturer of the antenna I mentioned above.

At an other SigInt site (formerly FAPSI, now apparently FSB) near the city of Pskov uses antennas made by the Andrew Corporation. So it is fair to say, that the Russians found a covert way to import intelligence-relevant material to their country even from the US, although you might argue, that there is a dual-use of a satellite dish.

Anyway would be nice to do some research on the origin of the Russian Torus antenna.

Here's the link to the second site with the Andrew-made atennas:

Great blog, really enjoyed reading!

P/K said...

Thank you for this additional information - very fascinating! I will take a look and hope to find out more. The antenna at the site near Moscow looks quite complex, so it's very well possible that it was custom made for this purpose, copied from the antennas they saw at the Five Eyes sites.

Anonymous said...

One more thing: There are even two Torus antennas at the (heavily secured) Egelsbach Transmitter Facility near the city of Frankfurt, Germany. The facility officially belongs to the US Army and you can find it in the BASE STRUCTURE REPORT, at least in the past few years you could.

The purpose of this site, which is located in the midst of a forest, not far away from the airport, remains unclear.

However, its close location to the Dagger Complex in Darmstadt (INSCOM) and the /th US Army in Wiesbaden (including the 66th MI Brigade) and its history suggests that it is operated by the US intelligence agencies: A few years ago it sent the voice of "Cynthia" (Numbers station). This is more than less verified. Cynthia silenced a few years ago, but the Egelsbach Transmitter facility remained - and was expanded. They now have radomes and new antennas, which mostly seem to be products of TCI.
Here's the location:
50° 0′ 14.77″ N, 8° 36′ 40.16″ E



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Drew said...

Really interesting article. Thanks for posting!

P/K said...

More information and photos of the large Torus-like antennas in Russia, can be found in this report: http://nautilus.org/wp-content/uploads/2015/05/Torus-SATCOM.pdf (pdf)

Rahul Kumar said...

Thanks a lot electrospaces for the informative post on satellite interception!!!

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Anonymous said...

Echostar has two General Dynamics torus antennas in Gilbert, AZ. ATCi has a location in Chandler, AZ with a demo Simulsat antenna onsite.