US spy satilite uplink locations? - Page 1
Forum section: electronics / general

author: CopperCone
author_rank: Super Contributor
timestamp: April 24, 2018, 01:51:07 am
content: Is this information classified?I figure that these guys do the analysis;https://en.wikipedia.org/wiki/National_Geospatial-Intelligence_AgencyBut what does the signal chain look like? Does the satellite basically beam down encrypted data in packets that are unlockable by anyone with a key, or do you log in with secure terminals to get download access with specific encryption (i.e. you need to communicate with the satellite)?Where does it get received (don't see any big microwave dishes on the roof of that building)? Is it put on the internet on secure servers?Good reading material on this part of space intelligence? I can find a fair bit on physical construction and stuff like that, but not the so called back end.

author: Halcyon
author_rank: Unknown
timestamp: April 24, 2018, 05:43:08 am
content: As you can well and truly imagine, most of the information about these facilities, operations, equipment and personnel are classified, but not all to Secret or Top Secret level. Many government ground stations worldwide are known to the public but not all are visible in satellite images. Radomes for example not only protect the dishes from the elements, but also prevent the direction in which the dishes are pointing from being known.All information is encrypted at least once and protected networks are completely separate from anything even closely connected to the internet. Most data processing is done off-site inside buildings you may have unknowingly driven past. Those covert sites are not known or published to the general public and only those with a "need to know" are aware of their locations.In Australia anything classified as "Protected" and above is generally not delivered over the internet, encrypted or not. Other methods are used, such as private networks, physical handling via "safe hand" etc...Anything you find on the internet is generally unclassified and is public knowledge. Even the information in the Snowden leaks wasn't particularly sensitive or detailed. Anything else, you won't have access to and those that know won't tell you.

author: BradC
author_rank: Super Contributor
timestamp: April 24, 2018, 06:16:01 am
content: Quote from: Halcyon on April 24, 2018, 05:43:08 am

author: daqq
author_rank: Super Contributor
timestamp: April 24, 2018, 06:52:55 am
content: QuoteThere are actually funny methods of modulation that, even if you know the frequency of the data, you are not able to actually receive the data. The GPS signal is actually below the thermal noise of receivers (a physical limit) making it indistinguishable from noise even when received. It's a CDMA modulation, basically, you can't receive it unless you know what kind of code is being sent. So even if you make a sweep with a spectral analyzer, you won't find a peak.I'm not saying that this is the way they transmit, but it would make sense.

author: bd139
author_rank: Super Contributor
timestamp: April 24, 2018, 07:12:38 am
content: I worked close to this side of things many years ago. It has probably changed now but it was dumb as chips originally. All the info is public so I’m not breaking any rules here. There were some persistent problems with foreign actors jamming the uplinks. They all use phased arrays now instead which allow jamming signals to be dealt with, although not sure how that works. Think uplink/downlink is X-band/Ka-band. Most of the comms sats are simple relays. Protocols change and are service dependent. Modulation is nothing clever usually I understand, PSK or QAM. You can actually listen in on a VHF scanner if you have a suitable receiver on some of the older FSK channels. I didn’t go anywhere near the transport side of things.Ground stations are mostly airgapped but depends on service.Lots of different services run through them so it’s hard to be specific as to usage. There is a TNC network however which allows secure channel chat between two nodes for example. Ship to shore etc. Keys are preshared. There as a big PDF of how this works on the vendors web site but I can’t find it now as they’ve been bought out twice since I last looked at it.Nothing exciting or secret. Only the imaging and “dark” satellites are surprising and no one knows anything about them of course, even most of the people working on subsystems and integration don’t know the full picture. Mostly satellites are for access where there isn’t any ground infrastructure or it got blown up.

author: Halcyon
author_rank: Unknown
timestamp: April 24, 2018, 07:57:22 am
content: Quote from: BradC on April 24, 2018, 06:16:01 amThis.Unless you work in the relevant industries, it's unlikely you even know someone who knows. Most people with specific knowledge lie about where they work and what they do, often with quite ordinary jobs so you won't ask too many questions. Hiding in plain sight if you like.

author: bd139
author_rank: Super Contributor
timestamp: April 24, 2018, 07:58:37 am
content: The information is all out there. Start with defence contractors’ sales brochures

author: chickenHeadKnob
author_rank: Super Contributor
timestamp: April 24, 2018, 08:31:19 am
content: Going back to the mid seventies there was the true spy story of Christopher Boyce who worked in the black vault room of TRW. Made into a book and movie called The Falcon and the Snowman. In the book it mentioned Boyce was a "walk in" in that he just walked into the Soviet embassy in Mexico City ungroomed and unsolicited and handed over the company store. TRW made the comm gear for the NRO. One of the projects he revealed to the soviets was a satellite that was to appear dead on orbital insertion, a malfunction so that the soviets wouldn't be bothered to cover up when it passed over. It would however actually still be working and sending its telemetry upwards to a geo synchronous relay. So even back then there was subterfuge and misdirection over what was going on with sat comms. In the book it mentions Boyce's interrogators visibly blanched when he mentioned which of the projects (called pyramidr or something like that) that he turned over.

author: CopperCone
author_rank: Super Contributor
timestamp: April 24, 2018, 01:54:41 pm
content: Quote from: daqq on April 24, 2018, 06:52:55 amWhat do you mean? All i can relate to is a lockin amplifier but i dont know how the q compares to a reciever. I understand a lockin has a q better then 10000 usually

author: schmitt trigger
author_rank: Super Contributor
timestamp: April 24, 2018, 02:11:50 pm
content: I remember "the Falcon and the Snowman".Good movie. Better book.

author: Cerebus
author_rank: Super Contributor
timestamp: April 24, 2018, 02:54:53 pm
content: Quote from: daqq on April 24, 2018, 06:52:55 amIt makes sense just from a physics point of view, let alone security. As you imply, theprocessing gainavailable in a modulation like DSSS allows you to pull a minute signal out of the noise. Power on satellites is at a premium unlike any other, if you can reduce your transmit power by some cunning processing then it's worth it.

author: Howardlong
author_rank: Super Contributor
timestamp: April 24, 2018, 03:00:07 pm
content: Most Earth imaging stuff is LEO so typically a distributed network of groundstations is used to maintain continuous contact and maximise downlink utilisation, there’s not always much need for local antennas.One of the weirdest places I’ve done installations and deployments is at Svalsat up at 78 degrees North. There’s plenty of secret squirel stuff going on there.The biggest benefit of groundstations at the Poles is that they experience far more passes each day from polar orbiting LEOs than groundstations closer to the equator.I remember trying to fix a solid coaxial power splitter with the crappy 25W emergency iron I’d taken with me, it was a waste of time, and trying to locate a decent iron at that location wasn’t the easiest of tasks, I very nearly had to abort the job.We had an IP camera on a 19” rack cabinet in a strapped down shipping container adjacent to help remotely manage the setup. One day, I was conducting a final test before flying home, and my OH had joined me. While I was in the radome, she was in the shipping container and decided it was time to get changed in front of the cabinet, much to the excitement of the ground crew in the Netherlands.

author: Cerebus
author_rank: Super Contributor
timestamp: April 24, 2018, 03:01:45 pm
content: Quote from: CopperCone on April 24, 2018, 01:54:41 pmWaaay too involved to try and attempt a five minute explanation here. Start by reading aboutDirect Sequence Spread Spectrum, pay particular attention toprocessing gainand Carrier Division Multiple Access (the latter is used to prevent multiple users of the same RF frequency from interfering with each other, but can also the used for secrecy andlow probability of interception).

author: jmelson
author_rank: Super Contributor
timestamp: April 24, 2018, 09:59:42 pm
content: Quote from: chickenHeadKnob on April 24, 2018, 08:31:19 amOne of the things that Boyce apparently turned over was wiring diagrams of the teletype cipher gear used on Navy ships and many other places. This was of little value until John Walker turned over the old cipher keys, which he was supposed to supervise burning. OK, now the Russians supposedly had enough (recording of the ciphertext, diagrams of the encryption machine and the cipher keys) to read the messages. But, the story goes, it DIDN'T work. Apparently, the NSA intentionally put errors in the drawings of the crypto machines. Not of a kind that would impede a repair tech from fixing a machine, but would stop a foreign country from building a working machine.So, the Russians got the North Koreans to capture the USS Pueblo so they could get their hands on an actual crypto machine.NSA sent out a new PC board that had some wiring change to part of the encryption logic and just kept using the same machine.Jon

author: raptor1956
author_rank: Frequent Contributor
timestamp: April 25, 2018, 01:21:45 am
content: Russia and China and pretty much everyone else knows what and where pretty much everything is space is. The recent Zuma mission that was called a failure has also been suggested to have been a success that was merely labeled a failure to throw everyone off. If they were to relay to a higher sat so there's no emissions downward from it that would reveal its health, as has been suggested to have been done in the past, then it might well be functioning exactly as intended with the failure as a cover story.I doubt that's what happened, but it's not beyond the possible.Brian