GPS Transitions to New Control System 170
gsfprez writes "It took us a long time, but the Air Force has finally moved off of the 1970's mainframe GPS control system and is now running on a new Unix-based Control System called AEP — Architecture Evolution Plan. It's important to remember that current GPS satellites are basically solar powered iPod shuffles with atomic clocks that simply playback whatever we upload into them at a precise rate. They don't actually have any idea where they are — its the control system at Schriever Air Force Base that does. The new system will be a lot cheaper to support and modify since Sun stocks things like SATA drives - while digging up Saturday Night Fever-era DASDs isn't simple. AEP will also allow us to be ahead of the curve: we're basically good to go to fly the new IIF birds."
Re:will this (Score:3, Informative)
The system they are referring to here tracks the satellites and tells them what to say. The output will not change, just the method used to generate it.
i was edited and my points were lost.... (Score:5, Informative)
The new system is modern. You can buy the machines from Sun today online. The OS is still updated and supported. The parts are commonplace like SATA drives, USB DVD drives, Sun workstations, etc. Unix may not be some newfangled operating system, but i can line up 1000 unix-savvy 30 year old-ish engineers and sysadmins for every one 60 year old-ish engineer that understands how to work with the IBM mainframes and jovial.
The savings comes only to US taxpayers - because its going to be way easier to for "us" (US citizens) to pay for younger engineers that are not all about to retire and younger hardware and software that shouldn't have been retired 20 years ago. "We" (US citizens) can pay less to keep GPS going now. The rest of the world.. well, i can't help you with costs since you've never paid for this thing. I'd just say "thanks" and leave it at that.
the iPod shuffle reference is to the fact that all the shuffle does is get music uploaded into it and play it back... it does *nothing* else. Okay... with that example in your mind... that's the same basic thing that GPS satellites do... "we" (US citizens) upload them with what to playback, and they play it back - and they have a clock to make sure they play it back at the right speed.... they practically do nothing more than that.
yeah, my headline was shortend to save room, but in the end, i had to end-up retyping it here. I wish they would have simply said
Re:Confusion (Score:3, Informative)
It sounds like Richard Devine.
Re:Maybe My Imagination (Score:5, Informative)
Increased bandwidth: No, absoultely not in any way. Nothing is different parameter-wise with this transition from the user perspective. In fact, that was one of the hardest parts of the transition - to make the new system interact with the user segment (thru the Space segment.. aka: the satellites) in the exact same way as the old system.
I apologize for not being more specific than that... i also stated in my submission that i am extremely hesitant to say anything unless i'm 100% sure that its public knowledge.
So, if you think i'm beating around the bush, you're right. I'm not doing it for effect.. i'm doing it to keep my job and because security is paramount.. not just for US folks, but for everyone that uses GPS.. and i hear a few people are getting into it these days... kinda like CB radios and that Internet thing.
You should have seen the old system (Score:5, Informative)
The previous system, installed at the Satellite Control Facility [209.165.152.119], or "Blue Cube" (Onizuka AFB) in Sunnyvale, was physically huge. It was the Technology that Put Men On the Moon: Philco consoles, just like in Apollo Control.
Each time a satellite needed a trajectory adjustment, it took three computers and lots of people. The signal processing was done in something called an Emulated Buffer Controller, which was a transistorized device emulating a previous tube device. The real-time processing was done on one of several UNIVAC 490 series machines from the 1960s, and the trajectory computation was done on a CDC 3800 mainframe from the 1960s.
All this gear was interconnected through big manual patchboards, where, for each satellite pass, people plugged in cables to pass data from the ground station links to the buffer controller to the UNIVAC machine to the CDC machine to the console system.
This operation just drove the satellites, not the payload. The USAF, in a very Air Force way, makes a strong distinction between "driving the bus" and operating the payload. Anything that involved commanding the satellite to move or change orientation went through the Satellite Control Facility. Payloads (GPS, cameras, receivers, etc.) were controlled by the using agencies elsewhere, over separate data links.
The SCF's ground stations had (and still have) large (20 meter) steerable dishes that can communicate with their satellites over a low-bandwidth link regardless of the satellite's orientation, even if it's tumbling. There are about eight ground stations, spaced around the world, and they can track as well as communicate. Once the satellite is properly stabilized and oriented, the wide bandwidth directional links used by the payload come up. Those use smaller ground antennas, so as not to tie up the big tracking dishes.
This was finally phased out in the late 1980s, when control moved to Falcon AFB. Still, during the entire history of the Satellite Control Facility at the Blue Cube, no satellite was ever lost due to an operational error there. That's partly why upgrades were delayed.
The upgrades generally maintained the structure of the system, without doing a complete redesign. (A complete redesign was tried once, in the early 1980s. It flopped.)
Re:Confusion (Score:4, Informative)