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WAAS up with this?


Tracker Don
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With all the posts on getting reception from the new WAAS sats, I though I'd like to find out from other eXplorist users if they actually do get WAAS.

 

I live in NJ and my eXplorist 500 (ver 2.03) shows green W's on the sat screen with no numbers. The position screen does not indicate WAAS. When I was in Wisconsin this summer, the Position screen accuracy box had "WAAS" in it and I think the Sat screen had numbers with the W's. Why am I not getting this in NJ? Also there appears to be no difference in accuracy in NJ with the WAAS on or off.

 

BTW, when in Wisconsin and "WAAS" was showing in the accuracy box, I was getting 3'-6' accuracy. In NJ the best I've ever seen was 16', and have never seen "WAAS" in the accuracy box.

 

So I'd like to hear what all your eXplorists are indicating about WAAS at your location(please list).

 

Thanks,

 

Tracker Don

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So I'd like to hear what all your eXplorists are indicating about WAAS at your location(please list).

Magellan firmware only uses WAAS satellites that are transmitting data marked as good for aviation use. Thus, while the new satellites are in "test mode," Magellan receivers will not use them. Since you are in NJ, the older WAAS satellites are pretty close to the (west) horizon, so it's not too surprising that you are not seeing WAAS corrections.

 

That should change soon, as the new WAAS satellites go fully online. In fact, I think that one of them is scheduled to do so in the next couple of weeks.

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My eXplorist 600 gets a WAAS link almost every day. I see the "W" on the satellite page, and I do not always show WAAS in the box on the position summary page, but it is usually there at some point in my commute to work/home. I live in north-eastern IL (near the WI border) and my accuracy seldom goes below 10 feet, but I have seen it down to 7 several times. Most often, I am in the 10-30 foot range, although usually in the 10-16 foot range when it shows WAAS.

 

I may be mistaken, but I thought you had to be near an area that had the ground based "augmentation" sites in order to get WAAS updated/adjustments. If this is the case, you might be too far away from the ground based stations to get the WAAS benefits.

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I live in SC and get WAAS corrections apparently from 48 and 51, even though they are in test mode. I know this because I get the D on my satelitte page for the satellites. 35 keeps making a sneak appearance also but is weak. Accuracy is around 7-9 feet. 51 was showing a solid bar a few days ago, now it's a transparent bar.... 48 has never had a solid bar lock.

 

The one thing I am curious about, it seems that the unit gets a lock on them for about a minute, then loses the lock, then gets it back after another minute like they are being turned off and on. This happens even if I am keeping the unit still in an open farm field here. The satelittes keeps showing D under them even when the WAAS signal drops for a short period.

 

Is this normal or are they simply just testing 48 & 51 before they are fully funcational.

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.

 

I may be mistaken, but I thought you had to be near an area that had the ground based "augmentation" sites in order to get WAAS updated/adjustments. If this is the case, you might be too far away from the ground based stations to get the WAAS benefits.

 

No, no, no. This is the whole idea of WAAS. You do not have to be near a ground station! All the data is uploaded from ground stations and the master station makes a universal model of the ionosphere, sends the correction data model to the WAAS sats and your GPS figures out where it is in that model, and applies the proper corrections. As long as you are in the area of the U.S. you are good to go, as long as you can see an active WAAS sat.

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Here is a good way to visuallize both the ionosphere AND the data correction model for WAAS. First of all, consider how this model undulates. Notice how it has the highest activity during the day and the further south you go. Now picture you and your GPS somewhere below this net. Your GPS figures out where the closest data points in this net is (where the threads cross) and uses one or more of those data points to correct for an active ionosphere.

http://gpsinformation.net/exe/iono-day.gif

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Thanks for all the info, keep it coming! After checking some of the links in your posts I found this tidbit from http://www.gpsinformation.org/dale/dgps.htm :

 

Magellan use of WAAS

 

Magellan uses WAAS in a similar way to the description of Garmin use given above. However they do not have a menu item to turn WAAS on or off. There is a secret menu entry that can do this. Turning off WAAS frees up some channels for regular satellite use and should certainly be performed if you are outside a WADGPS coverage area. As already mentioned Magellan does not display the WAAS satellites on the satellite status screen so there is no indication on the unit whether WAAS is turned on or off unless you are actually receiving WAAS signals. When you are receiving WAAS the epe indication changes to show WAAS and when averaging a position the WAAS indication is present. Note that the unit will continue to use WAAS corrections long after the signal is lost. Some report that corrections will be used for 50 minutes or longer as indicated by the WAAS averging indication. (It is not clear from the report that WAAS data is still being used or it is just a software bug.) If you power the unit down and back up the use of this stale data will be discontinued.

 

In looking at all the maps of WAAS base stations and satillites, it is still curious that the "WAAS" doesn't show up on my position screen. It may be as it says above,

When you are receiving WAAS the epe indication changes to show WAAS and when averaging a position the WAAS indication is present.
, but for some reason in NJ i'm never getting this.

 

BTW, I contacted Magellan "Support" via email before I posted my original question here and as of yet have recieved no reply, other than a "Thales Navigation Technical Support Survey" asking me to rate my satisfaction with their response. I bet you can't guess what my reply was <_<

 

Tracker Don

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Yesterday I did a "clear all memory" and restarted my explorist. I opened up the "secret" WAAS menu and watched as it aquired satillites. I saw it find 134 ( which is #47 or POR, a WAAS sat) and then replace it with 122 (# 35, AOR-W also WAAS) and 120 (# 33, AOR-E, which is an EGNOS sat). It settled on 120 and 122. Why is it maintaining 120 if it is an EGNOS sat? THat is probably why I'm not getting good WAAS. THe Satillite screen had 2 green W's but no bars with a W and no "WAAS" in the Position screen.

 

After walking though some woods to a field behind my house, and finally I had a very short green bar with a W showing under it, but again, no "WAAS" in the position screen. I checked the "Sercret" WAAS menu and was getting data in the "SNR" field for 122, but 120 was still just "srch" with no data.

 

I think if I could keep the 134 sat and the 122, I'd be alright, but the GPS seems to want to keep the EGNOS sat, 120 instead. How can I fix this?

 

(magellan still hasn't gotten back to me)

 

TD

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Yesterday I did a "clear all memory" and restarted my explorist. I opened up the "secret" WAAS menu and watched as it aquired satillites. I saw it find 134 ( which is #47 or POR, a WAAS sat) and then replace it with 122 (# 35, AOR-W also WAAS) and 120 (# 33, AOR-E, which is an EGNOS sat). It settled on 120 and 122. Why is it maintaining 120 if it is an EGNOS sat? THat is probably why I'm not getting good WAAS. THe Satillite screen had 2 green W's but no bars with a W and no "WAAS" in the Position screen.

 

After walking though some woods to a field behind my house, and finally I had a very short green bar with a W showing under it, but again, no "WAAS" in the position screen. I checked the "Sercret" WAAS menu and was getting data in the "SNR" field for 122, but 120 was still just "srch" with no data.

 

I think if I could keep the 134 sat and the 122, I'd be alright, but the GPS seems to want to keep the EGNOS sat, 120 instead. How can I fix this?

 

(magellan still hasn't gotten back to me)

 

TD

 

What is the "secret" Magellan menu to turn off WAAS and is that something I want to do? I live in North Alabama. The DVD discussed here http://www.nohvcc.org/IMAGES/prgps.asp says to to turn off WAAS. Lo and behold, a review of my Magellan Sportrak Pro shows no menu setup to turn off the WAAS feature.

 

Thanks,

 

AR-15

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What is the "secret" Magellan menu to turn off WAAS and is that something I want to do? I live in North Alabama. The DVD discussed here http://www.nohvcc.org/IMAGES/prgps.asp says to to turn off WAAS. Lo and behold, a review of my Magellan Sportrak Pro shows no menu setup to turn off the WAAS feature.

 

Thanks,

 

AR-15

 

AR-15, I'm not sure how a Sportrak works, but on the explorist if you press the "menu" button then move the joystick left and right about 4 times it opens the "secret menu" enter "03" to open the WAAS screen. The only thing you can do on the explorist using this is to turn WAAS on or off. Here's where you go for more info:

 

http://rhamphorinkx.newmail.ru/sf.htm

 

TD

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What is the "secret" Magellan menu to turn off WAAS and is that something I want to do? I live in North Alabama. The DVD discussed here http://www.nohvcc.org/IMAGES/prgps.asp says to to turn off WAAS. Lo and behold, a review of my Magellan Sportrak Pro shows no menu setup to turn off the WAAS feature.

 

Thanks,

 

AR-15

 

AR-15, I'm not sure how a Sportrak works, but on the explorist if you press the "menu" button then move the joystick left and right about 4 times it opens the "secret menu" enter "03" to open the WAAS screen. The only thing you can do on the explorist using this is to turn WAAS on or off. Here's where you go for more info:

 

http://rhamphorinkx.newmail.ru/sf.htm

 

TD

 

Does anyone know what this website is for or why magellan dosent mention anything about it in the owner manual,instructions?

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Does anyone know what this website is for or why magellan dosent mention anything about it in the owner manual,instructions?

Because there is no reason to turn off WAAS on a Magellan unit.

 

I dont want to turn off waas off but I thought that there might be something on the "secret menu" that could help me be able to download the newer firmware onto my 500. I havent been sucessful in getting any help from magellan either.

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I dont want to turn off waas off but I thought that there might be something on the "secret menu" that could help me be able to download the newer firmware onto my 500. I havent been sucessful in getting any help from magellan either.

Unfortunately, the secret menu stuff won't be able to help you with that; firmware uploads are handled only via the computer connection. The secret menu screens are diagnostic screens that can show you satellite status, etc.

 

Magellan has a much superior WAAS implementation to that of Garmin; there is really never any reason to turn WAAS off for Magellan units. Those people who claim that doing so makes their units "more stable" are experiencing a classic case of what is known as "confirmation bias."

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What is the "secret" Magellan menu to turn off WAAS and is that something I want to do? I live in North Alabama. The DVD discussed here http://www.nohvcc.org/IMAGES/prgps.asp says to to turn off WAAS. Lo and behold, a review of my Magellan Sportrak Pro shows no menu setup to turn off the WAAS feature.

 

Thanks,

 

AR-15

 

AR-15, I'm not sure how a Sportrak works, but on the explorist if you press the "menu" button then move the joystick left and right about 4 times it opens the "secret menu" enter "03" to open the WAAS screen. The only thing you can do on the explorist using this is to turn WAAS on or off. Here's where you go for more info:

 

http://rhamphorinkx.newmail.ru/sf.htm

 

TD

 

Does anyone know what this website is for or why magellan dosent mention anything about it in the owner manual,instructions?

Because these keystrokes are dangerous and magellan does not want to get sued for a feature that they might have made widely known. Actually, since magellan claims that they did not give any instruction whatsoever on how to do this they can void your warranty if you tell them that your unit locked up from doing this. All legal flab.

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