This is double-plus bad.

The Wall Street Journal
June 18, 2009
GPS Satellite Glitches Fuel Concern on Next Generation

By Andy Pasztor

Technical problems are degrading the accuracy of signals from the last GPS satellite launched by the Pentagon, sparking concerns among U.S. military and aerospace industry officials that the next generation of the widely used satellites could face similar troubles.

The Air Force's Southern California space acquisition center on Tuesday announced that a Global Positioning System satellite, manufactured by Lockheed Martin Corp. and launched in March, is experiencing performance problems in orbit. It hasn't become part of the "operational constellation" of more than two dozen other GPS satellites, and is slated to undergo a battery of tests expected to stretch through October to try to resolve the problems, according to an Air Force news release.

The GPS system, which serves both military and civilian users, provides precise time and location coordinates for everything from military missile launches and "smart" bombs to automated bank-teller machines to aircraft, ships and everyday vehicles. The Lockheed satellite is the first to include a new civilian frequency -- dubbed L5 -- designed for, among other things, use by future nationwide air-traffic control systems. But that signal, part of test package, apparently is interfering with other signals from the satellite and reducing their accuracy, according to industry and Air Force officials. The degraded signals are accurate only to about 20 feet, versus about two feet for typical GPS signals, industry officials said.

The issue is significant, according to these officials, because it could complicate deployment of a new family of Boeing Co. GPS satellites currently being built that also feature the L5 signal. Already years behind schedule and hundreds of millions of dollars over budget, the 12 satellites, which are scheduled to replace satellites currently in orbit, could face further testing and delays to ensure that they are free of interference problems. The Boeing satellites have a history of quality-control and manufacturing problems unrelated to the latest concerns.

While the Air Force said it has "high confidence there is no related concern" with other Lockheed satellites in orbit or waiting for launch, Air Force brass have begun examining whether Boeing versions of GPS satellites require additional tests and analysis to eliminate concerns, according to industry officials familiar with the details. A spokeswoman for Boeing declined to comment. A Lockheed Martin spokesman said the company is working with the Air Force "to fully evaluate the issue and to ensure the satellite meets GPS requirements."

In its release, the Air Force said the routine in-orbit checkout of the suspect Lockheed satellite revealed that some signals "were inconsistent" with comparable GPS satellites. The Air Force also said upcoming tests will include simulations and "testing of real-life GPS receiver equipment to the greatest extent possible" to prevent "inadvertent impacts to GPS users."

The first of Boeing's GPS IIF satellites, incorporating the new civilian signal, is slated to launch late this year or early 2010, delayed from the summer.

In May 2008, Lockheed bested Boeing to win a contract worth at least $1.8 billion to build the most-advanced navigation satellites yet, dubbed GPS III, scheduled to go into operation around the middle of the next decade.

Concerns over signal quality come barely weeks after a Congressionally-ordered study raised a red flag about potential erosion of GPS accuracy in the next few years due to launch delays and other challenges. If certain launches get delayed up to two years, the General Accountability Office report predicted, the Pentagon could have trouble maintaining the desired fleet of 24 fully-functional GPS satellites in operation.

The Pentagon responded by minimizing the potential risk, arguing that significant spare capacity remains on orbit and on the ground to handle unexpected problems. Gen. Robert Kehler, head of Air Force Space Command, said in an interview earlier this month that the GAO conclusions were overly pessimistic partly because they failed to take into account strategies the Air Force could use to extend the life of existing satellites. For example, Gen Kehler said, managing power output could give solar arrays longer life.

Despite some continuing quality-control issues with Boeing's IIF versions, Gen. Kehler said, "we're not going to have an issue" maintaining the current robust constellation.

Huh. Map & compass, anyone?

A single Lock-Mart spacecraft has an unexpected performance problem on-orbit. The program very prudently orders a review of the potential for the same problem on unlaunched spacecraft of both Lock-Mart and Boeing manufacture. It's a delay. It's a frustration. These things happen.

The GPS constellation needs to be replenished. This problem will delay that replenishment. And just based on the article, this seems like the kind of problem that should have been found during ground testing. So a large pot of $$$ may have been squandered. That's pretty bad by any reasonable standard.

Rapidly diminishing skill.

If worse comes to worst, they launch the birds in time to replenish the constellation and never activate the L5 channel. This would be a graceful fail from a nominal capability set to an acceptable, if less than desired, capability set. No catastrophe involved.

If the worst doesn't come, they fix the problem and carry on.

We don't need no stinkin' compasses! Atleast not here in the Central Europe where village density is high enough that it's usually enough to walk an hour to get exact fix by village name

Ever try to consult a map and compass travelling 40 kph on a bike? My GPS tracks elevation and grade data as well.

Yep, land nav skills are dying, if folks have forgotten how to stop periodically to check location and direction... There are also the times the GPS database is wrong. I've had this happen a time or two with the GPS in my car. Yes, I do keep maps handy.

When I was a Mission Pilot with the Civil Air Patrol, it was fun to turn off the GPS and watch the observer quietly freak while he struggled with map and plotter to determine position and direction--which he should have prepared for as part of his mission prep.

The whole point is not stopping, your heart rate drops, your legs cramp up, etc. Also the GPS stores detailed ride data so I can see how I did during various climbs, etc.

Carrying a detailed map on a bike when you aren't touring is a pain in the ass too.

Not sure how that works in a Predator or a JDAM.

Your observer was not familiar with a compass, sectional chart, and NBD/VOR?

Simple enough to figure out where you are at without having Magellan.

VFR = Visually Follow Roads

IFR = I Follow Roads

Ditto

Don't get me wrong; I looove GPS! I do courier work and if it weren't for my GPS, I probably would still be wandering around New Orleans, from a visit a year and a half ago!

As awesome as the things are though, backup is comforting.

Besides, using a map gives another incentive to look at the surroundings.

The scary thing is that too many pilots are depending on "Direct To" and ignoring (& forgetting) pilotage and ded reckoning. A friend who is an active pilot tells me that he is seeing these skills being neglected in flight training.

My bike GPS (a birthday present from Naomi-chan) uses Ordnance Survey map cards. I therefore have a detailed map, with my position marked, & any route I've loaded shown overlaid on the map, sitting on my handlebars. Also good for walking.

Are you able to access the maps if the GPS goes down?

Whilst I agree that map reading and using a compass are important skills that still should be learned, still like what Kenneth said: JDAM and other GPS-guided ordnance and UAVs won't be able to work just as well without GPS (they sure can't fold out a map and bring out a compass as they hurtle towards the target).

[quote name='shep854' date='Thu 18 Jun 2009 2318' post='681983']
Are you able to access the maps if the GPS goes down?
[/quote

ALL. This discussion evokes memories of navigating with a map ,and compass, only in pre-GPS days. Mention of no problems in closely settled areas may be alright in areas where one is fluent in the local l;anguage and script. Not everyone uses a Latin script.I can recall being almost totally unaware of my, our , location in Japan on a map reading exercise in japan due to the great multiplicity of towns/villages in a relatively small area until we came on a town where the Post Office was signposted in English or at least the Latin script.Alternately it may have been Romagi the Japanese rendering of the Latin alphabet..
And again in Seoul one morning when looking around the city on my own this time a fog descended. My knowledge of Korean being even more lamentable than my skills in Japanese scripts.
I thought I might mention that there are at least two(2) other global positioning networds availabe in orbit and working the European and the Russian Glonass. Their use might not be politiacally desirable. WB

Wallaby Bob has a point; skill at "Charades" will always be useful...

Maybe it should be added to E&E curricula.

I have the Edge 705 - my only complaint is that without a pre-planned route I find the map too small to navigate on the fly in completely un-familiar locations while going at a good clip.



Yes.

Don't military maps have town names in both english as well as local script?

Glonass is currently in a state of disrepair for global use.

Galileo is still in development.

If the device fails, no. If it can't access the GPS network - yes. But being the fuddy-duddy old conservative that I am, I generally carry a paper map anyway.

The value of the GPS to me is that it shows location & pre-planned route, & can be mounted on the bike handlebars where I can see it all the time. A paper map in a map clip shows neither location nor route, is much more draggy (yes, that makes a difference) & needs frequent removal & re-folding. Paper maps are hard to keep dry while mounted where they can be seen, & plastic maps have permanent folds which aren't necessarily where you want them when mounting the map on the bike.

Paper maps are far better for route planning, & I plot routes on a computer with a decent size screen & mouse, rather than the poky little GPS screen & fiddly controls.

Horses for courses.

Doesn't help if you're trying to match the names on the map to those on signs to find out where you are.

Especially if the locals remove/change signs. After all, screwing with outsiders is a universal sport with many locals, especially the juvie types.

I stuff my back pockets with more important stuff, like food and tools

Maps are fine, but I find them redundant unless you are so out in the middle of nowhere you can't ask for directions.

Agreed, I did more navigation by BallpeenHamerdorfs. Only time I used a map was when I went into the woods.

You've described most of my rides.

Even in densely populated SE England, country lanes aren't exactly crammed with people, & off-road rides are worse. When you do encounter a local, you find them au fait with good driving routes, but struggle to think of routes which avoid main roads.

When I go out on the bike, I don't aim to get from A to B by the shortest or fastest route, I aim to follow a route I'll enjoy. Being passed by a constant stream of cars doing 70mph is not fun.

I find using a well planned route basically completely eliminates getting lost - I can't remember the last time I used the actual navigation functions of the unit, its much more of a training tool for me, having the graphical course on screen is pretty sweet though for the first time I do a ride course.

What sort of bike do you ride?

I have a Roberts Audax (Columbus tubing, Campag pick 'n mix from Chorus down to Mirage), which is what I do most miles on, an old Kona mountain bike, a Brompton folder for commuting & pottering around town (ridden most often but short distances), & a new titanium road bike (with Campag Centaur - to replace the Roberts) which I'm not riding at the moment because I'm waiting for new forks for it. The makers cocked up the measurements & it doesn't have the toe clearance I'd asked for. Bumping toes on the front wheel all the time.

What is the fork rake? I ride race geometries and I only bang my toe doing 180 deg hairpin turns at slow speed - if its that tight you might run into stability issues as well.

No, it's not that tight - but it's not a race bike, it's meant to do day rides (sometimes all day), audaxes, & maybe a little light touring occasionally - therefore it has mudguards. Without them, there's enough clearance, but not enough with them. I won't mind the more relaxed ride the extra fork rake will give, though. It'll be like the Roberts, but lighter, & a slightly softer ride. That's OK as well. It's what I wanted. I may get a Carradice saddlebag to rub in the point that it's not a pure speed machine, in case the Brooks saddle (B17 Narrow, 18 years old & going strong, on its 3rd bike) doesn't make it absolutely clear.

The choice was between a major refurbishment of the Roberts, & a new bike, & I decided to spoil myself. Expensive, but it's meant to last a long time (won't rust ). They're getting Ti forks made for it, because they can't source carbon ones with the right rake. I could have had steel fairly quickly, but the hell with it, if I'm buying a once in a lifetime bike, I might as well go the whole hog.

What do you have?

I've got a bunch of bikes - my workhorse road bike is a cervelo soloist, but I've got a Qroo caliente for TTs. I've also got a rockhopper comp, an old steel Limongi, a surly steamroller and a K2 astral I use for winter biking. I'm also building up two bikes: an OEM carbon racer and a 1975 gios torino super record.

I refuse to use fenders

I'm slowly getting into frame building too.

The STS* navigation system was wonderful, but was decidedly lacking in coverage in the forests as several slightly less than able map readers learned to their dismay.







*Sign to Sign

Chaingang in an English winter without them & whoever's behind you gets a faceful of filth. And when you want a break from the front, you suffer the same. The brown stripe up the back is also unappealing. On a fine summer day, mudguards are a drag, but they're damn useful at other times.

Why the hell would anyone feel the need for 3-4 bikes
I could see 2 if you love mountainbiking, but 4!!??

Fast road bike.
Mountain bike.
Folder for commuting by train.
Utility bike for shopping, riding to the pub, etc. (I used to have one . . . )

I cna go on nad on, sport. Plenty of other niches to fill. I know people who have a good racing bike, a second quality one for training rides, a fixie for posing urban riding, a tourer for holidays - and that's just road bikes, before we get on to utility, off-road, pure fun, etc. I know a couple of people with antiques they sometimes ride, including one who has been known to ride her Ordinary to work. As she said, if you're the official office nutter, you may as well live up to it. A bloke I know (saw him today) once sold four of his bikes to help pay for another one he wanted. His total was still in double figures, & with his wifes & kids bikes the family had about 30. Maybe slightly OTT.

"Maybe slightly OTT."

Ahh, that incredible British reserve...

You can easily own 3-4 different off-road bikes alone: A dual suspension cross country/trails bike, a downhill bike, a dirt jumper, a 29ner, a single speed and a trials bike.

I've got a TT bike for, well time trials and triathlons and a high end road bike for racing and group riding

Geometry is totally different:





On top of that I've got a bike for winter riding, a steel road bike for commuting and a single speed track bike just cuz.

I easily spend 20 + hours a week on bikes.

Holy ****!
Compare that to my mother, still using the same bike (note, singular) as ~38 years ago (she did get a new saddle a few years back though!)

does your mom bike to work, race, do MTB and go on group rides for 100-200 km with paces in the mid 30 km/h range? Its all a question of how much you bike. A single inexpensive bike is sufficient for most people - I'm not most people.

Believe me, I got that point!

My solution was to move to a well signposted small island with open terrain and lots of readily identifiable landmarks visible day and night (wind turbines and lighthouses). It's worked great so far.

Even a frumpy, lazy, beer-swilling lump like me finds it handy to own more than one bike and I've never been into the hardcore end of cycling.

Day to day general.
Off road decent.
Road bike for distance rides.

I could easily envisage owning five or six bikes minimum for anyone in the hardcore world of cycling.*

* I define 'Hardcore' as any man willing to leave the house in bike-pants or any form of sporting leotard.
(And please for the love of all things sacred NOBODY post a picture of Jason in tights, my mind is screwed up enough! )

Said B'rer Rabbit...

Like my partners mother. A single speed bike with dynamo lights & a basket for shopping. It does for her, but I wouldn't want to ride it on the 111 hilly km I did today.

Hey! I'm hardcore!

you simply cannot do long rides on a road saddle without a chamois...also if you don't wear spandex you're fighting a hell of a lot of extra drag for a long distance.



how about a pic of Liz Hatch's legs?