WAAS-- how available?

[Guest Chris Juricich]

My understanding of WAAS (a feature I'm looking for on my next unit) is primarily only available in North America. OK, fine, but I get the impression that our WAAS-enabled units won't necessarily be able to take any regular advantage of it.

 

In other words, it's inconsistent, or maybe it depends on where you're using it. Is there a convenient ground station for WAAS along the coast but you're out of luck if you're in Colorado? Arizona?

 

There are limited ground stations being used for this?

[Guest xsintrik]

WAAS stands for Wide Area Augmentation System. It is not ground based. A WAAS enabled GPSR recieves the WAAS signal from a geosynchronous satellite. PRN 47 is over the Pacific and should be visible to your GPSR if you are in Arizona. Of course it depends on your GPSR's ability to "see" the satellite. PRN 35 is over the Atlantic and it is the one that my GPRS "sees" here in eastern Texas.

[Guest Peter Scholtz]

Are they over the equator? Does it mean they'll be visible from South Africa?

 

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Peter Scholtz

www.biometrics.co.za

[Guest Moun10Bike]

onent to WAAS (roughly 25 ground stations are involved). See this web site for more info.

 

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Jon (Moun10Bike)

31H/93F

N 47° 36.649', W 122° 3.616'

www.switchbacks.com/geocaching.html

 

[This message has been edited by Moun10Bike (edited 18 September 2001).]

[Guest bob_renner]

Yes, they are over the equator, and should be visible from South Africa. However, the correction information they transmit is based upon ground stations in N. America. The corrections you would need may not be the same as what is being transmitted and may make things worse than not using WAAS. The system is still new and not fully implemented. Things may change in the future.

 

Bob

[Guest mrgigabyte]

quote:

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PRN 47 is over the Pacific and should be visible to your GPSR if you are in Arizona. PRN 35 is over the Atlantic and it is the one that my GPRS "sees" here in eastern Texas.[/b]

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Actually, this is not the correct nomenclature. SV 35 and 47 are Garmin's satellite numbers and ONLY apply to Garmin gpsr's. Another gps manufactures would use another labeling system. AOR-W  is located over eastern Brazil at N 0.0 W 54.0. POR is located over western Samoa at N 0.0 W 179.0. You may find them easier to locate if you enter them as waypoints into your unit, then 'Goto' that waypoint to find the exact direction to it from your location.

[Guest ClayJar]

As to the other half of your question, how useful/available it is, in Louisiana, I have WAAS locks a substantial amount of the time (basically, always on the roads, and quite often while hiking). I don't live in CA, of course, but I find WAAS nicely useful in this section of the country.

[Guest Iron Chef]

quote:

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Originally posted by Moun10Bike:

Actually, there is a significant ground-based component to WAAS (roughly 25 ground stations are involved). See this web site for more info.

 

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There is also a significant ground-based component to the regular GPS satelites which is namely the builders: Boeing and others. Even though the WAAS ground stations help in the correction measurements, they do not transmit any DGPS correction themselves that can be accessed by a GPSR (unlike the coast guard stations and older beacon based DGPS system that had land-based transmitters for correction on the high seas). The signal is uploaded to the WAAS birds which then spread the love around the globe.

 

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-Iron Chef

_ _ _ _ _ _ _ _ _ _ _ _ _

agefive.com/geocache/ ~ Fe-26

Lets Drive Fast and Eat Cheese!

 

[This message has been edited by Iron Chef (edited 18 September 2001).]

[Guest Moun10Bike]

quote:

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Originally posted by Iron Chef:

Even though the WAAS ground stations help in the correction measurements, they do not transmit any DGPS correction themselves that can be accessed by a GPSR (unlike the coast guard stations and older beacon based DGPS system that had land-based transmitters for correction on the high seas). The signal is uploaded to the WAAS birds which then spread the love around the globe.

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Correct. However, as bob_renner mentions, the ground stations have to be in your neck of the woods in order for the differential signals that they transmit to have meaning for your specific location.

 

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Jon (Moun10Bike)

31H/93F

N 47° 36.649', W 122° 3.616'

www.switchbacks.com/geocaching.html

[Guest Kerry]

These are the satellites that transmit WAAS corrections. The following are interactive which will show visibility for a particular location.

 

However just being able to see these is irrelevant unless one is located within the network of ground stations which actually collect and compute the corrections (mainly atmospheric type corrections).

 

As far as I'm aware the signals have now been confined to the practical coverage limits of the ground station network?

 

http://www.lyngsat.com/tracker/inmar3f4.shtml

 

http://www.lyngsat.com/tracker/inmar3f3.shtml

 

Cheers, Kerry.

 

[This message has been edited by Kerry (edited 18 September 2001).]

[Guest xsintrik]

In my original post I was oversimplifying. I didn't want to try to explain the entire system. I just wanted to explain that the signals that the GPS recieve are from satelites.

[Guest Chris Juricich]

All well and good. Now I'm more confused.

 

So, WAAS is a signal that is delivered to the GPSR in my hand, the position of which is supplemented by ground based locations which, in tandem with the GPS satellites, provide my GPSR with greater accuracy. Yes?

 

Now-- I'm still unsure if it actually would work here in CA or not! I'm thinking it would, but...

[Guest Chris Juricich]

Moun10Bike-- thanks for the reference to that website... http://www.gpsinformation.net/exe/waas.html

 

Now can anyone say in simple English what the hell the website is trying to tell me?

 

PRN? Inmarsat? Garmin Satellite ID? So am I presuming correctly that if I note that one of my satellites being acquired is '47' that I've tapped into the requisite satellite that allows for the WAAS corrections to be applied?

 

These websites... !@#$%!! technospeak!!

[Guest Moun10Bike]

quote:

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Originally posted by Chris Juricich:

Now can anyone say in simple English what the hell the website is trying to tell me?

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I know what you mean -- some of these sites assume you already know what they are talking about, when the whole purpose of you going there is to find out information! One site that does a better job of explaining WAAS in "plain English" is the FAA's site: http://gps.faa.gov/Programs/WAAS/waas.htm.

 

I also like Garmin's page: http://www.garmin.com/aboutGPS/waas.html.

 

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Jon (Moun10Bike)

30H/93F

N 47° 36.649', W 122° 3.616'

www.switchbacks.com/geocaching.html

[Guest Chris Juricich]

Thanks, Jon-- it certainly explains it a lot more simply than the gov-speak the other one provided for.

 

One thing I'm still trying to dope out is-- on my Garmin eTrex (the baby of the bunch) my 'advanced sky view' screen lists a bunch of satellite icons on the screen, each with a number, and below, a pair of numbers for each satellite, presumably, with a bar indicating the strength of the signal being received.

 

On one of the websites attempting to describe WAAS, they mentioned that Garmin had its own numbers for these satellites. The Pacific area satellite was designated (Pacific Ocean Region--POR) '47' according to the Garmin folks on their units.

 

So, if I'm with a Garmin WAAS-enabled unit and I'm not getting satellite #47, then WAAS wouldn't be working for me...???

[Guest tecmage]

Hi,

 

I started following this thread last night. Tracy and myself were out geocaching and realized that we had exceptional reception. At one point, our Legend was locked on eight or nine sats with WAAS corrections on four! Our estimated error was reading 9-10 feet!

 

Richard and Tracy

[Guest Moun10Bike]

quote:

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Originally posted by Chris Juricich:

So, if I'm with a Garmin WAAS-enabled unit and I'm not getting satellite #47, then WAAS wouldn't be working for me...???

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Correct -- you need to pick up #47 and/or #35 (Garmin's designations) in order to get WAAS corrections. I've actually been able to get both at times up here in Washington State. They are extremely low in the sky, though, so you need a pretty clear view of the horizon.

 

One thing -- you mentioned that you had the "baby of the bunch" eTrex. Do you mean the original yellow one? If so, then you will not be able to get WAAS corrections. Only the Venture, Legend and Vista models in the eTrex line have WAAS capability.

 

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Jon (Moun10Bike)

30H/93F

N 47° 36.649', W 122° 3.616'

www.switchbacks.com/geocaching.html

[Guest Chris Juricich]

Oh, I knew my lil' yeller eTrex couldn't get WAAS-- it's why I'm sniffing out for my next one. Currently creaming over Garmin's

GPSMap 76. Bigger screen, finer detail, maps, bells, whistles, etc. sigh

 

Anyway, spending $350 (or less on eBay) isn't high on my agenda right now, and my little eTrex still works as well as any of the non-WAAS ones out there for my money.

 

Why do I want WAAS? Simply so that when I place my cache, I won't have to dick around with averaging. What a bother! But is it worth $300 plus bucks? Not yet-- for me.

 

Besides, WAAS is kinda pointless when you think about it, unless the fellow who placed the cache had it on his in the first place. Both on the same page, right? Otherwise, if someone used averaging to position their cache, my WAAS wouldn't make all that much difference, would it?

[Guest Choberiba]

Personally I think coughing up cache..er. cash for the feature du jour would be a bit of a waste.

 

For pretty much every other situation a non-WAAS GPSr is fine.

 

Hunting and placing caches is supposed to be fun. You Californians and your goofy ideas.

[Guest Choberiba]

Personally I think coughing up cache..er. cash for the feature du jour would be a bit of a waste.

 

For pretty much every other situation a non-WAAS GPSr is fine.

 

Hunting and placing caches is supposed to be fun. You Californians and your goofy ideas.

[Guest Iron Chef]

Also important to note is that sometimes you get better accuracy with WAAS turned off. Since the WAAS birds sit so low on the horizon they may only be visible 10% of the time you are out there doing your thing and the rest of the time their signals may be blocked by something. In cases like that it may be worth it to see if there are any regular birds up in the sky that want to help you out. Just a thought.

 

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-Iron Chef

_ _ _ _ _ _ _ _ _ _ _ _ _

agefive.com/geocache/ ~ Fe-26

Lets Drive Fast and Eat Cheese!

[Guest Chris Juricich]

All this talk dissing WAAS!

 

I'll admit to an awareness that WAAS isn't always a system that is very reliable, but hey! I don't care-- I'm a neuvo-techie and I enjoy the tech part of the devices as much.

 

Oh well. So the bird sits low on the horizon, eh? I'd be seeking out no. 47, I think, in the air, the Pacific Ocean Region WAAS satellite. Well, I'll let you all know how it works out.

 

Why a WAAS enabled GPSr might not receive more specific coords than a non-enabled device isn't clear to me from your explanation, IronChef!

[Guest Chris Juricich]

And hey! WAAS is hardly a 'feature du jour', I think. It's something like HD TV, I suppose-- not everybody has it, not everyone is broadcasting in that form, etc.

 

It seems like the next regular thing, such that WAAS-enabling will be standard in a short time.

 

Nyaah! Nyaahh!!