GPS - OVERDUE FOR A RETHINK?

[cleo]

Hmmm. I'm being exhorted by a trad beardie who works for IPC Magazines to change my ways and stop bothering to cross-check my nav information. Seems it's all right now, he's checked out the GPS system and he tells me that it's utterly reliable. Now, this is in the pages of one of IPC's mags. And since I bought it, there's a contract. And the old gent cannot pretend that he's not a 'professional', so there's a higher duty of care that the courts would expect to see, in the event that I - or you - took his professional advice not to bother to check navigational nformation derived from the GPS system any more, and had an 'incident' as a result.

Well, what bothers me is that the US authorities - DoD, USAF, Volpe Center - having been warning anyone who would listen for some months now that the GPS system we all have embraced is increasingly unreliable. In fact, they've stated in official reports that "The implications are too serious to endorse GPS as the only navigation system for operations", "GPS is an ageing system , with 18 of the 28 satellites beyond expected design life", that the first launch of the planned replacement system 'GPS 3' ( Block 3 ) has slipped to 2009, and that the future of WAAS in in doubt. All the professional navigation journals are carrying articles on the implications, and another US industry leader in navigation systems writes that "The nail is in the coffin of GPS as sole-means navaid. It's not safe...."

The bolt from the blue, of which nothing seems to have been printed by IPC Mags anywhere, is the 'Volpe Center Report on the Vulnerability of GPS'.

It states a number of facts quite unambiguously: "The aviation and maritime sectors must be aware and adopt mitigation strategies..... Integrity checking and checking against known positions by small craft at frequent intervals..... Be prepared by not relying fully on GPS, dusting off those older once well-established navigation skills, and keeping the paper charts and plotting instruments.'

Magazines such as Defence Daily News ( Special Reports ), Avionics Magazine, International Tugs and Salvage all carry their own warnings to readers.

Here? Zilch!

Our own Royal Institute of Navigation held an Open Meeting in June about this, with guest expert speakers from the US FAA and elsewhere. So what was said?

I can get by, once again, by cross-checking the stuff I intend to use before relying on it. Always have. But lots of others will want to see it in print - preferably in their favourite colour mag. So how's about it, IPC? Let's have an authoritative article on the true implications, warts and all, from a good journalist who does not have a book on GPS on the shelves needing promoting, or who does not rely for part of his living on any commercial linkage to the integrated yottie GPS industry.

Reputations are at stake. Maybe. So also is the safety of unsuspecting yotties!

And you may well wonder why there hasn't been a peep out of Eastleigh, despite the stand-up bollocking that the MCA handed out to them about standards just a few weeks ago.

Remember, you heard it here first.

Cleo

bilbo

 

[Chris_Stannard]

My experience wa of a GPS that started giving funny readings, which turned out on examination to be caused by an ingress of water leading to corrosion on the circuit board.

GPS is as you say only an aid to navigation and should be used in conjunction with all the others. Incidentally the IMO Resolution on passage planning, ANNEX 24 says and I quote

" Close and continuous monitoring of the vessel's position ensuring as far as possible that different methods of fdetermining position are used to check against error in one system"

I did not see the article to which you refer but, on the basis of your post, the advice given is clearly outside of this requirement and the author is at fault.

Chris Stannard

 

[Rob_Webb]

Interesting post. I, for one, was unware that GPS is quite so far down it's expected lifespan and if this is true, the implications are signifcant for small-boat navigation. It would almost seem like a return to the dark ages of RDF fixes!

But I am baffled by how the service could really become so degraded. Given that it originated as a position-fixing tool for the US military, surely they will continue to need that? Or is it just that the US don't intend to make future generations of GPS available to the public (and therefore a potential enemy)?

Rob

 

[Twister_Ken]

SO GPS is on the blink. That'll be why HMS Whoopsie hit a pointy bit of Australia, then.

 

[bedouin]

Too late - they've turned off most of the RDF stations (along with Decca...)

 

[summerwind]

Well, it had to happen I suppose. For years we have been hearing that GPS is no good because it is a new fangled gizmo that can't be relied on.

To be sure of where we were we had to have a sextant (one knock and it is out), stars that, especially this summer, we can't see, a spinning wheel running through the water that is inaccurate because of banacles, weed etc, a lump of lead on a piece of string and paper charts that are based on surveys done by iron men in wooden sailing ships.

Now we are told that GPS is no good because the system is too old!

Lot of bollocks IMHO.

 

[kdf]

Agreed. No way GPS is going to dissapear. Look at all the U.S. companies using GPS to run their business - Trucking companies, trains, Fexex, Hertz plus the U.S. military. Cycling the sat's is part of the normal maintenance of the network and there's plenty of redundancy built in.

RDF? What's RDF?

 

[Guest]

A couple of years ago the RYA, Royal Navy and others got together at a Royal Institution of Navigation symposium and agreed that the greatest hazard of GPS was complacency. Best practise, which was being mooted then, was discussed and most agreed that GPS should be used in conjunction with all other systems available. HMS Dryad, for instance, the Royal Navy's school of navigation, teaches comparison of radar, GPS, depth, DR and any other sensors. Only by using all the methods available can you develop sound personal judgement. This way the EP, mental or otherwise is used to backup the GPS plot and vice versa. That's the way navigators learn to trust themselves, rather than any single system or instrument. Seems obvious really - no-one should keep all his eggs in one basket. The worst aspect of GPS though, is that it discourages triangulation of a course, or course to steer as RYA instructors call it. And that makes for a lot of lazy sailing, and time-wasting.

 

[poter]

Yes I have also seen the comments re the degrading of the GPS system and was not amused having just spent a considerable amount on a new GPS.
But surely the USA Gov. and military will have to update the system sooner than 2009???

Also won't the european GPS system be on line soon?

Hmmm. will my nice new GPS be able to use the europe system?

poter

 

[cleo]

'Dear Dan' has it about right. The RIN's symposium on 'Use and Abuse of Electronic Aids' was finally just about unanimous re. all this. RIN Small Craft Group Secy John Jeffrey's printed summary had it spot on. Bears reprinting.

Essentially, the DoD et al are asking us to look out the window now and then. Just check the darn things are doing what they oughta. That's what pro aviators and pro shipmasters are supposed to do - required to do - and it surely isn't onerous for us to look up from the latest Desmond Bagley now and then and have a squint at the world outside. Costs nowt - might save 'egg on face'.

But we all know them - those wot loudly say to all who'll listen - "I paid good money for this thing. The salesman told me it was accurate to the width of my cockpit, and that I could park my car in my Sales Director's reserved space with it; I could even line myself up with the home porcelain with it..... And I'm determined to get my money's worth come rain, hail and ( visibility of less than 1000 metres ). See, it has a readout for the direction of my favourite pub, the step-by-step way to the nearest Travelodge, my 21-foot boat's speed to seven places of decimals, and a thingy that reminds me when the eggs are boiled. Great, isn't it? Don't know what I'd do without it.....

Eh? What sticking-up rock?"





bilbo

 

[Guest]

Cleo,
Maybe we can put this right - at least in MBY.
Could you please contact me by private email so I can learn more about your information sources? On the aviation side, the FAA seems to be going ahead with plans to use GPS as a precision runway approach aid, which doesn't tie up with stories of it becoming less accurate or reliable.
Look forward to hearing from you.

 

[gtmoore]

Some info on GPS future in "Latest News" at http://www.gpsworld.com/gpsworld/ although doesn't really describe degradation in the system as discussed above - more about how the US are cutting funding to the GPS replacement (GPS III?) and enhancing the existing system. They do say that current GPS satellites are performing years beyond their anticipated lifetime and that they can delay replacements without compromising the current system.

HTH

Gavin