US GPS satellites going off

[sucksqueezeBANGstop]

Hello there bright people,

My brother just casually mentioned this morning that the USA are considering encrypting all the GPS signals for a couple of years - said he heard it on BBC Radio 2 Jeremy Vine show yesterday.

Does anyone know if this is true, and how it may effect GPS users?

I don't really use a GPS much in the air so I am not panicking! Honest. :D

Thank you,

SSBS

[Feathers McGraw]

The report you have heard is incorrect. What this is probably related to is the Government Accountability Office in the US stating that in their opinion the progress on launching more Block IIF and Block IIIA SVs is behind where it should be due in part to changes in project management.

At present there are 31 SVs in orbit, of which 24 are required for a full constellation so there are in-orbit spares.

Provided that the launch schedule does not slip further, it is unlikely that significant degradation of coverage will occur.

There is no intention to turn on the Selective Availability feature, it was turned off for good in May 2000 because ways of denying GPS usage in a given area have been developed.

[kbrockman]

USA are considering encrypting all the GPS signals for a couple of years - said he heard it on BBC Radio 2 Jeremy Vine show yesterday.

There is no real talk about encrypting anything at all, there are however ongoing mounting problems with existing satellite reliability, as of last week there where as many as 8 (out of 31) satellites at the final stage of permanently breaking down, meaning one technical failure away from total loss.

Normally it was planned that the maintenance/replacement was scheduled to start 3 years ago but the whole program has severely (where have I heard that before? :ugh: ) overshot its budget (between 800mill-1 bill$) and has run into serious delays.

In November 2009 the first replacements/maintenance is planned to go into effect but they first need to get the go ahead from the budget oversee commission because they overshot the budget by a too wide margin.

That's what I understood what's going on, plz feel free to correct me if I'm wrong.

[AnthonyGA]

The signals will not be encrypted; SA will not be turned back on.

There is some concern that the Air Force is not keeping up with its planned schedule of satellite replacement. It is highly unlikely, however, that the GPS system will fail, or even become degraded. The satellites are being upgraded as well as replaced, even though an upgrade is not essential for system stability; it's the cost of upgrading that is most likely holding up the program.

The cost of maintaining GPS is a drop in the bucket compared to the amounts of money being thrown out the window by the government in so many other domains, so the problem is likely to be more one of proper accounting and administration than financial hardship or technical difficulty.

[anotherthing]

There are hundreds of civvy applications that are GPS enabled, and millions of them sold every year... it always strikes me as odd that Garmin et al do not have to pay a percentage of each sale of a GPS enabled unit to the budget holders responsible for the upkeep of the sat system.

It wouldn't have to be much, maybe 1 or 2 % of each unit sale, but it would go a long way to funding what is in actual fact, a military application that civilians have been granted use of.

[green granite]

SA will not be turned back on.


With the general availability of DPGS there is no point in turning SA back on as it can send out the pseudo-range corrections required for nulling out the deliberate fed in errors.

[aviate1138]

anotherthing ended.....

"It wouldn't have to be much, maybe 1 or 2 % of each unit sale, but it would go a long way to funding what is in actual fact, a military application that civilians have been granted use of."


I thought the civilian US population originally funded GPS via their income taxes?

[Double Zero]

Anotherthing,

Couldn't agree with you more, and I must admit I feel that rather than getting in a huff because they / we didn't invent it first, the European version of GPS seems an extremely expensive case of re-inventing the wheel.

As a civvy user of GPS crossing the English Channel, well I did it a lot a while ago by traditional methods ( am still a good boy and do them for backup ) but in the days of 'Karwe' RDF with a 30 degree null ( or no signal at all ), GPS was an unimaginable dream.

It would be jolly handy, ideally tied in with the camera, ( coming into fashion now ) for aerial photography too - it was not uncommon in a later life for me & young CPL to ' arrive ' over a target town, when I had to say ' I know X quite well, and wherever we are isn't there '!

Before anyone says it, yes I should have been more help with the navigation, but young pilots who've paid a lot for their training don't take kindly to suggestions - this is maybe worth noting as a general thing, not aimed at any individual.

[WhatsaLizad?]

I think the encryption story is false, but I'm all for it. My vote as a US citizen is that all future GPS satellites have the capability to selectively offer it's services to the users. Geographic considerations would be the first criteria. Any unit used in North America and the US territories could be used without charge or restrictions. Canada, Mexico and the Caribbean nations included. Any N-numbered aircraft, and US registered vessel or other US based commercial interest also pay nothing. All other commercial units would be licensed and a fee paid for use of the system. It is a product or service like anything else we use. Like any product, it would have to be priced competitively in light of other nav systems that could be brought on the "market" by the ESA, Russia or the Chinese.

I've already "paid" my part for it. (I know I may be just have made loan "payments" on it, and the Chinese actually "own" it, but that's another thread :E)

[411A]

All other commercial units would be licensed and a fee paid for use of the system.

What a superb idea...a GPS license fee for foreigners.
Example.
Individual users...$50/year, commercial users $5000/year.
Per unit, of course.
Yup, that should do it alright:ok:

[Double Zero]

And how does giving lives in any war you feel like naming -
unlike others, count ?

[Mark in CA]

How about ad supported GPS? You'd have to watch a 15-second advert before you get your fix. :E

[FrequentSLF]

I thought the civilian US population originally funded GPS via their income taxes?

Yup...but the US population paid it as an instrument of war and the USAF is maintaining it still to be used as an instrument of war. There is not guarantee of being operating at any given time. If the USAF decides to pull the plug...that' it...if you want to charge for the use of it...you should also lay down T&C and be liable when is out of service.

[LH2]

I don't know if it's still the case, but before widespread availability (i.e., 80's and 90's) it used to be a requirement that GPS equipment manufacturers had to have at least one manufacturing facility in the U.S., thereby creating local employment.

[keith smith]

1.I believe the GAO report is unduly pessimistic,written by people whose knowledge of satellite navigation is limited.they didn'trelate their predictions to RNP degradation,which is what matters to aviation.
2.Although the USAF (not Army) is responsible for procuring and operating GPS (although not some of the high performance augmentation), the next generation of ATC for commercial aviation (NextGen in US,SESAR in Europe) relies on the twin rocks of GPS and ADS-B.This means that the US government will not allow GPS to fail,perhaps apart from a very minor hiccup.
3.GAO warned of "competion" from Europe (amongst other places), which shows how litle they know.The EU hasn't even let the main contract yet, and they have been faffing about for years. If it wasn't for a relatively small company based at Surrey University, Galileo would have been a no show. The frequency allocation was only temporary,and if the timescale was not met,the communication industry would have gobled it up forever.
4.GPS and Galileo are not in competition if they are mutually compatible
(and they are supposed to be) the more satellites in view, the merrier as far as RNP is concerned:):)
Keith

[cwatters]

A spokesperson (from GOA?) was interviewed on the BBC Rado today. She said that about half the existing 31 were beyond their design life or had problems of some sort (I think thats what she said). Basically she was saying that at current predicted failure and replacement rates the number may drop below 24 sometime in the not to distant future.

[finfly1]

In addition to the tens of thousands of civilian users of car navigation and cell phone tracking systems, it was my understanding that the FAA had [finally] approved official GPS approaches for many smaller airports which did not have an operating ILS.

To let the system fail would have been unthinkable for the government to do, at least up until recently.:ugh:

[b377]

Back in the mid 90s when GPS first achieved IOC and shortly after FOC the FAA's future air navigation system (FANS) actually envisaged the shutting down of all terrestrial nav aids ( ILS, VOR, MLS, ADF ...) in favour of GPS as sole means within a decade or so ...

Of couse WAAS and the GPS constellation, plus infrastructure, have come some way towards that end but how ever did the FAA ever even entertain such notions is quite unbelievable today. Talk about putting all your huevos in one basket? No wonder it all went pair shape.

GNSS has now moved on from the technical challenges of the 90s but these have been replaced, now that the world has woken up to realise the importance of this utility, by political ones - the outcome of all this is that GNSS will sooner rather than later cease to be a free asset not only because of the need to fund its upkeep but to capitalise on it. The Military will by then have evolved their own successor system leaving the civilian world to fend for itself. The Europeans have traditionally levvied tax or fees on everything, Galileo will be no exception and GPS will follow suit.

[keith smith]

GPS or any SatNav is very susceptible to simple jamming,and with high powered jammers (fairly readily made) and suicidal terrorists a major TMA could be taken out for some time.
Everbody agrees there must be some backup, butno conclusion yet as far as I can see. E-Loran is a contender and DHS are seemingly backing that
(apparently the world banking falls apart again if ther is no timing to nano-
seconds!). Another possibility is mixed GPS/inertia where the INS is "calibrated" while the GPS is working--good enough to land.Nobody seems to be making up their mind:rolleyes:

[411A]

it was my understanding that the FAA had [finally] approved official GPS approaches for many smaller airports which did not have an operating ILS.


Yes, only recently....about ten years ago.:rolleyes:

[keith smith]

411A
WAAS was certificated about 5-6 years ago, and individual approaches have to be cleared.The European equivalent (EGNOS)also based on GPS still hasn.t been cleared
Keith

[reynoldsno1]

Most of the original (Block I) satellites exceeded their design life by at least 7years ... this seems to be an *rse covering exercise ....:ouch: