One Of Two WAAS Satellites Failed

 

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Ooops

Brush up on your charts and Mark 1 eye ball.

--
nuvi 855. Life is not fair. I don't care who told you it is.

Leaving one west coast bird...

The pending loss of Galaxy 15 will be felt by more than GPS users! Its WAAS footprint mainly added far-Northern users; folks below the Canadian border are still well covered by the remaining WAAS bird.

As the articles say, that does leave WAAS in a single point of failure mode, with no quick fix in the making.

And there are a lot of handhelds and built-in systems that don't have WAAS.

Cheers--

--
Nuvi 2460, 680, DATUM Tymserve 2100, Trimble Thunderbolt, Ham radio, Macintosh, Linux, Windows

Do "Consumer" GPS' use WAAS

Do the consumer Grade GPS's such as Garmin Nuvi's use WAAS? If so, would it just represent a loss in accuracy, or would there be other issues?

Beas

Optional or Not

billbeas wrote:

Do the consumer Grade GPS's such as Garmin Nuvi's use WAAS? If so, would it just represent a loss in accuracy, or would there be other issues?

Beas

With older units such as my C550, it is user selectable. I understand that with the Nuvi's it is always on.

--
I support the right to keep and arm bears.

Really?

You may be right, but I thought the nuvi's did not have WAAS capabiity. I never see it on the satellite screen. I do see the WAAS satellite on my DeLorme as #138.

--
Alan - Android Auto, Nuvi 3597LMTHD, Oregon 550T, Nuvi 855, Nuvi 755T, Lowrance Endura Sierra

I think I read that the

I think I read that the Nuvi's do not use WAAS due to the number of sat's they use for data, This was from Garmin. My problem is I can't remember the link to absolutely confirm. sorry
Virgo

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Virgo53 Nuvi 780/265W

Satellite

Glad that I live way down South. Although having only a single bird is concerning.

Not nessasary for me

I don't think I am going to miss it much. Most of my uses are riding my bike and driving my car, where the accuracy just is not that important. I imagine they will replace it sooner rather than later.

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Will nuvi 265W, Vista HCX, amateur radio

always on

billbeas wrote:

Do the consumer Grade GPS's such as Garmin Nuvi's use WAAS? If so, would it just represent a loss in accuracy, or would there be other issues?
Beas

Although it is not mentioned in the documentation for many nuvi models, it is apparently there and "always on". Some advertisers mention the nuvi supporting WAAS, and the actual accuracy of the device would seem to confirm this. Another USB based gps device that I have for use with a PC also has WAAS "always on".

"Always on" is a poor design choice, since it can actually degrade performance in areas not covered by WAAS (pretty much everything except North America). Perhaps if any good comes out of this failure it will be for manufactures to quit making WAAS an "always on" option and give users control of it, but in reality the general dumbing down of technical things seems to indicate that this is unlikely to happen. And this failure will not effect most North American users.

Wolfram Alpha to Locate Satellites in the Sky

Since the topic is a satellite, one easy way to locate a satellite in the sky is to use the Wolfram Alpha computation engine at:

http://www.wolframalpha.com/

Then enter the name of a satellite such as Galaxy 15. Not only will you get a diagram of where it is in the sky at the current time, you'll also get a bunch of stats. Or, enter "gps satellite" and get a whole kaboodle. The orbit isn't too interesting for geo-stationary birds like the WAAS satellites, but if you enter one of the GPS ones like "navstar 22" the orbit is more interesting.

Or, enter the name of a city, or sports team, or mathematical problem... have fun!

probably depends on the model

alandb wrote:

You may be right, but I thought the nuvi's did not have WAAS capabiity. I never see it on the satellite screen. I do see the WAAS satellite on my DeLorme as #138.

My "old" NUVI 350 has the option of turning WAAS on or off. I never saw much difference, so I leave it turned off.

-jgracey

--
I have seen the future and it is now!

not a big deal to me

I've had GPS units for more than a decade, and I have turned WAAS on and off many times trying to see if it helped. I couldn't see any tangible difference either way.

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___________________ Garmin 2455, 855, Oregon 550t

Nuvi 660 has it

My Nuvi 660 Has WAAS and the option for turning it off. I thought models after that lost WAAS but I can't prove it.

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NUVI 660, Late 2012 iMac, Macbook 2.1 Fall 2008, iPhone6 , Nuvi 3790, iPad2

FAA

Glad the FAA decided to get rid of ground radar and switch all commerical aircraft over to GPS.

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Nuvi 3790LMT, Nuvi 760 Lifetime map, Lifetime NavTraffic, Garmin E-Trex Legend Just because "Everyone" drives badly does not mean you have to.

WAAS as per Garmin

Here is Garmin's description of WAAS: http://www8.garmin.com/aboutGPS/waas.html

As for using WAAS, when I fly with my Garmin 296 in the central US, I almost always have a WAAS signal. When I drive with the same unit, it's almost always "searching for WAAS." So, on the ground I've found WAAS to be relatively useless.

To locate the end of a runway, 3 meters makes a difference. To locate an entrance ramp or a store front, 15 meters will do just fine.

WAAS Off -

geochapman wrote:

My Nuvi 660 Has WAAS and the option for turning it off.

I leave WAAS off on my 660. I don't do much flying and - from what I can get out of it - WAAS is much more useful for pilots than drivers.

some like our GPs receivers to be accurate

trigon wrote:

....WAAS is much more useful for pilots than drivers.

That strikes me as a poor way to look at it. WAAS is useful for anyone who really wants to know where they are. It is useful for drivers who what their GPS to know if they are on the Interstate or on the parallel service road, or who want to be sure to get the turn message as the approach their turn not after they pass it, or who similarly want the red light camera warning as they approach the intersection and not once they go through it. I can't think of any reason not to want the extra accuracy.

WAAS only gave me ~2 ft accuracy

My Nuvi 350 had WAAS and an option to turn it on or off. I ran comparison tests and the reported accuracy was never more than 2 feet better with it on than with it off. I think with a GPS system that only locks on to 2 or 3 satellites it might be more important or useful. But I don't think it makes much of a difference when you are locked on to 5 or more satellites at one time.
I'm sure there are many people out there who will be impacted by this, though.

Accuracy

If the question is, do you want more - or less - accuracy from your GPS? I think the easy answer is more.

Garmin's comments certainly make WAAS appear a strong positive:

Garmin wrote:

Okay, so what the heck is it? Basically, it's a system of satellites and ground stations that provide GPS signal corrections, giving you even better position accuracy. How much better? Try an average of up to five times better. A WAAS-capable receiver can give you a position accuracy of better than three meters 95 percent of the time. And you don't have to purchase additional receiving equipment or pay service fees to utilize WAAS.

And the simple argument earlier, would you like to know if you're on a service road or highway, makes a great deal of sense to urban users dealing with tight clusters of intersecting streets, spaghetti interchanges, narrow lots and idiosyncratic street names or numbers.

So yes, WAAS is important. Important like a pilots responsibility, no - but important and useful nonetheless.

"WAAS ... is an average of up to five times better (accuracy)"

--
17

WAAS

On my 350 I have the ability to either turn WAAS on or off. I have tried it both ways and the accuracy did not improve much at all. So, I don't use WAAS since it really doesn't matter to me if I am 2 feet or 5 feet from an intersection. (At 30 miles per hour, it really doesn't make a difference.)

--
It is impossible to rightly govern a nation without God and the Bible. ----George Washington

Hmm.

You'd think this would have been picked up and mentioned in the Alaska newspapers, but I didn't see anything in searches.

I'm still concerned since my daughter works for the state and has to fly to most of it's smaller villages.

A reminder to give her a call and see how she's doing, me thinks. Thanks for the link.

--
It's about the Line- If a line can be drawn between the powers granted and the rights retained, it would seem to be the same thing, whether the latter be secured by declaring that they shall not be abridged, or that the former shall not be extended.

Nuvi350

The NUVI 350 has a setting for "WAAS/EGNOS"
either on or off.

--
Don't sweat the petty things and don't pet the sweaty things!

http://www.n2yo.com/whats-up/

--
According to the laws of aerodynamics, bumblebees cannot fly. But the bumblebees, not knowing the laws of aerodynamics, go ahead and fly anyway...

Disadvantages of WAAS

Frovingslosh wrote:

...WAAS is useful for anyone who really wants to know where they are. It is useful for drivers who what their GPS to know if they are on the Interstate or on the parallel service road, or who want to be sure to get the turn message as the approach their turn not after they pass it, or who similarly want the red light camera warning as they approach the intersection and not once they go through it. I can't think of any reason not to want the extra accuracy.

There was previous discussion on the disadvantages of WAAS, including higher power drain and less accuracy at highway speeds. See http://www.poi-factory.com/node/5698

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Garmin StreetPilot c530, Mapsource

Hand held

My hand held 76CSx has WAAS. I leave it turned on all the time and get good accuracy.

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GPSMAP 76CSx - nüvi 760 - nüvi 200 - GPSMAP 78S

rationalization

mkahn wrote:

.... There was previous discussion on the disadvantages of WAAS, including higher power drain and less accuracy at highway speeds.

I had seen this in the past. My thought on it is that it is very unsupported by fact or logic and that it is just a personal rationalization for not using WAAS, perhaps made by people who lack the feature and are trying to feel better about not having it.

Lets look at the two arguments, each on their own merit:

As to power, I haven't seen any hard numbers to support this and don't believe it. The GPS receiver does need to receive another satellite to get WAAS, but is hopping between satellites anyway. And the added error information is likely to simplify the math for getting a fix, so there are actually benefits to WAAS. Added to all of this, the power needed to light the display and provide audio is a big part of the power drain, I see no reason that a receiver running WAAS should really show more power drain with it enabled. Perhaps someone with a nuvi that has WAAS that can be disabled will measure power use with WAAS on and off, although even that would only tell us something about that particular receiver design. But without any numbers at all I think the power issue is urban myth. And is is really a non-issue for me anyway, as I power my GPS with an adapter on any long trip and keep the adapter handy even on short trips in case the GPS gets hungry.

I see no reason at all to believe that a WAAS receiver is LESS accurate "at highway speeds" and again simply question the validity of this statement. Why would anyone believe this to be true? WAAS provides an extra level of error correction to compensate for known propagation issues, how could that cause less accuracy? What does "at highway speeds" even mean? Everyone seems to accept that WAAS receivers are more accurate for pilots, and any aircraft, even small private craft, travel at "highway speeds" or greater, even when taking off and landing. Again, this just seems like a rationalization from someone who does not have, or thinks that they do not have, WAAS in their GPS.

I Just Read This...

http://en.wikipedia.org/wiki/Wide_Area_Augmentation_System

...and I think this issue isn't so much about what it used to do... but what it would do in the future, considering that sunspots are at their lowest in the solar cycle.

As they increase, there will be more and more ionization of the upper atsmosphere, resulting in more need for clock corrections.

That's the purpose of WAAS. To judge (don't ask me how, I just read it myself) the degree of correction required and to broadcast that correction, presumably for however much each satelite was off, to WAAS capable units.

If you look at the accuracy requirement... it's only "25 feet". It's primary use is to allow gps-enabled air navigation. I don't think us ground-pounders are going to suffer too much... and there appears to be alternative satellites they can bring online.

Perhaps by the time we need it (assuming my presumption about ionospheric changes is correct,) they'll have launched whatever is required to keep the system up.

--
The Wizard of Ahhhhhhhs - Earned my Windmill 4/12/2010

Interesting info...

Interesting info...

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http://www.poi-factory.com/node/21626 - red light cameras do not work

No problem for me here in

No problem for me here in central canada as long as 138 stays active.

Steve

I was driving car & using my

I was driving car & using my GPS at the time of failure.

Luckily I wasn't flying smile

Thanks for the info. Great to read.

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Street Pilot C340, nuvi 265WT, Mio Moov 300, nuvi 255W, Navigon 2100 (Retired)

Test on my c530 WAAS

Frovingslosh wrote:
mkahn wrote:

.... There was previous discussion on the disadvantages of WAAS, including higher power drain and less accuracy at highway speeds.

I had seen this in the past. My thought on it is that it is very unsupported by fact or logic and that it is just a personal rationalization for not using WAAS, perhaps made by people who lack the feature and are trying to feel better about not having it.

Just ran a quick test on my c530. With WAAS turned on, the unit seemed slower to update and actually missed some turns (reporting after I passed them. Granted I only did this test for a short time, but I am convinced to leave it in Normal rather than WAAS.

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Garmin StreetPilot c530, Mapsource