Which One?

[+DaemonLee]

What is WAAS, is it better for land? What's it used for?

 

Thanks, guys.

[+Thrak]

What is WAAS, is it better for land? What's it used for?

 

Thanks, guys. 

WAAS uses some fixed position satellites that allow your unit to get a more accurate location reading. In my area it is often quite difficult to get a lock on those satellites - I usually leave it turned off. If I'm up on the canyon rim or out in wide open spaces I sometimes turn it on. When I cached in Montana and Nevada I used it though. Lots of sattlite reception in those wide open areas. It DOES tend to eat your batteries much faster with WAAS on.

 

Something to consider is that many folks never turn it on so their coordinates weren't figured with that extra degree of accuracy. You might get to ground zero using WAAS but find that the hider's version of ground zero is 30 feet away. I've heard folks say that if they had a ton of money they'd buy a Trimble GPSr. I always wonder what good 8 inch accuracy (seriously!) would do you when the cache hider was using a yellow eTrex. Getting super accuracy to the listed coordinates isn't really going to help that much if the listed coordinates are off due to normal error from a "regular" GPSr.

 

Often The Force is what folks use to find the cache. The listed coordinates just get you close. I DO tend to turn on WAAS and see if I can get a lock on those satellites when PLACING a cache though. I want my placed coordinates to be as accurate as I can get them.

Edited January 29, 2006 by Thrak

[+JDandDD]

Thrak is right that WAAS is used to improve the accuracy. Its used to provide GPSrs with correction information for the inaccuracies that do occur naturally in the satellites. With the correction in theory accuracy becomes less than 3 meters. Thrak is also right about lock. Because they are fixed they are lower on the horizon and you can get blocked out, even having your body in between your GPSr and the WAAS satellite will block it out.

 

In my area I get WAAS consistently so I leave it on and it does seem to help. However, there are days that I can't get lock regardless of how I position the GPSr.

 

JDandDD

[+Poidawg]

Always have your WAAS turned on and make certain the datum is correct for your area of the world. I turned the WAAS off just to see the difference, and it took the unit about 15 minutes to do what it would normally do in about 1 minute. The difference was remarkable!!

[+Prime Suspect]

Always have your WAAS turned on and make certain the datum is correct for your area of the world. I turned the WAAS off just to see the difference, and it took the unit about 15 minutes to do what it would normally do in about 1 minute. The difference was remarkable!!

That doesn't really make sense. You should get slightly faster results with WAAS turn off, since their are fewer sats to deal with, and the computations don't have to include WAAS adjustments. If it took 15 minutes, I'm guessing you accidently wiped out your almanac data.

[+Cpt.Blackbeard]

I'm always reading here that WAAS eats your batteries but I leave it on continuosly with my Legend and the NiMH batteries last 18 to 20 hours, even using the backlight sparingly. So unless I were stranded in the wilderness I'd use it, and do.

[+Team Cotati]

What is WAAS, is it better for land? What's it used for?

 

Thanks, guys.

This might be of help: http://www.garmin.com/aboutGPS/waas.html

 

"Cache on Garth!!"

[+JohnnyVegas]

Just leave it on. there nothing to gain by turning waas off that is goig to make a difference in your daily goecaching adventures. Also it must be on for at least 15 minutes to be of any help. Your gps needs to build up a WAAS almenac to work, that takes about 15 min.

 

cache on

[+budd-rdc]

If in doubt, leave WAAS mode turned on for your GPSr. People in the past have mentioned why they turn it off, but consider them exceptions rather than the rule.

[+Poidawg]

For detailed information on WAAS check out - gpsinformation.net/waas

WAAS and its Relation to Enabled Hand-Held GPS Receivers

(26 Feb. 2003)

Statement from the FAA

WAAS is based on a network of approximately 25 ground reference stations that covers a very large service area. Signals from GPS satellites are received by wide area ground reference stations (WRSs). Each of these precisely surveyed reference stations receive GPS signals and determine if any errors exist. These

WRSs are linked to form the U.S. WAAS network. Each WRS in the network relays the data to the wide area master station (WMS) where correction information is computed. The WMS calculates correction algorithms and assesses the integrity of the system. A correction message is prepared and uplinked to a geosynchronous satellite via a ground uplink system (GUS). The message is then broadcast from the satellite on the same frequency as GPS (L1, 1575.42MHz) to receivers on board aircraft (or hand-held receivers) which are within the broadcast coverage area of the WAAS. These communications satellites also act as additional navigation satellites for the aircraft, thus, providing additional navigation signals for position determination.

 

The WAAS will improve basic GPS accuracy to approximately 7 meters vertically and horizontally, improve system availability through the use of geostationary communication satellites (GEOs) carrying navigation payloads, and to provide important integrity information about the entire GPS constellation.

 

If you check out Garmins blurb on WAAS it will advise that WAAS does indeed improve system availablility.

 

I went to pick up a unit for a friend, at the beginning of January and the guy I purchased the unit from was fooling around with it while waiting for me. Turns out he had turned the WAAS off. The unit took longer to lock on the sats and never got more than 4. On the way back to my place I was stuck in traffic, and decided to put both units on the dash to see how well they did. The unit with the WAAS off, had a much harder time locking on to the satellites, and staying locked on. As soon as the WAAS was turned on, the units performed exactly the same way, gathering the satellite information and locking on at exactly the same time. It was a testament to those with the foresight to develop the system to begin with.

[+Thrak]

I placed a cache yesterday and had WAAS turned on. I got a 7 foot accuracy reading. When I turned WAAS off I got a 15 foot accuracy reading. I was up near the rim of a canyon where I could get a good WAAS lock.

 

As for the battery usage - I posted that it uses batteries faster because I'm pretty sure Garmin says it does and others have said it does and because I've noticed that my "battery bars" seem to go down faster when I've had it turned on all day. The battery usage isn't really an issue for me though since I have good rechargable batteries and they recharge in only 15 minutes. I carry a fully charged spare set with me as well as a set of alkalines as an extra backup. I may just leave WAAS on all the time from now on. I really enjoyed seeing that 7 foot accuracy reading.

Edited January 30, 2006 by Thrak

[+bobbarley]

WAAS uses info collected from ground based stations. The closer you are to those stations the better accuracy WAAS provides. Up in nothern Canada the EPE (error) doubles when I turn WAAS ON!

Edited January 30, 2006 by bobbarley

[+Prime Suspect]

If you check out Garmins blurb on WAAS it will advise that WAAS does indeed improve system availablility.

 

I went to pick up a unit for a friend, at the beginning of January and the guy I purchased the unit from was fooling around with it while waiting for me. Turns out he had turned the WAAS off. The unit took longer to lock on the sats and never got more than 4. On the way back to my place I was stuck in traffic, and decided to put both units on the dash to see how well they did. The unit with the WAAS off, had a much harder time locking on to the satellites, and staying locked on. As soon as the WAAS was turned on, the units performed exactly the same way, gathering the satellite information and locking on at exactly the same time. It was a testament to those with the foresight to develop the system to begin with.

I think you've reached an erroneous conclusion based on a single incident. WAAS should not have an effect on how quickly you get a 3D lock.

 

If you're in a moving vehicle, and one of the GPS units has been set to Power Save mode, it's going to have a much harder time getting a lock. Since Power Save and WAAS are mutually exclusive, turning WAAS on may automatically turned off the Power Save mode.

[+Poidawg]

I will get my friend and see if it happens again...stay tuned

[+Thrak]

I went to pick up a unit for a friend, at the beginning of January and the guy I purchased the unit from was fooling around with it while waiting for me. Turns out he had turned the WAAS off. The unit took longer to lock on the sats and never got more than 4. On the way back to my place I was stuck in traffic, and decided to put both units on the dash to see how well they did. The unit with the WAAS off, had a much harder time locking on to the satellites, and staying locked on. As soon as the WAAS was turned on, the units performed exactly the same way, gathering the satellite information and locking on at exactly the same time. It was a testament to those with the foresight to develop the system to begin with.

OMG!!! ROFLMAO.......

 

WAAS has NOTHING - repeat NOTHING to do with getting a lock on other satellites! I don't know what your issue was but it had absolutely NOTHING to do with WAAS. That is just tooooooooo funny.

Edited January 31, 2006 by Thrak

[+triryche]

RE: WAAS and Battery Life...

 

There is a noticeable amount of extra battery drain on my Garmin eTrex Vista when WAAS is on. I would say batteries last 50% longer with it off but who cares? Bring extra batteries! I would rather have a couple extra sets of rechargeables in my pocket anyway and get the better accuracy!!

 

Mike

http://www.qsl.net/k9drx

[johndmann]

I've heard folks say that if they had a ton of money they'd buy a Trimble GPSr. I always wonder what good 8 inch accuracy (seriously!) would do you when the cache hider was using a yellow eTrex. Getting super accuracy to the listed coordinates isn't really going to help that much if the listed coordinates are off due to normal error from a "regular" GPSr.

For $5,300 they can keep their GPS unit! I'm happy with my sub-$500 one personally!

[+Vinny & Sue Team]

I always leave WAAS on, and personally, for our SporTrak Pro and Explorist 100, have never noticed that its usage significantly affects battery life. The few experiments I have done with using WAAS versus not using it have convinced me that -- at least in most parts of continental USA -- WAAS helps quite a bit! And, our SporTrak Pro has no problem getting WAAS lock-in even under dense forest cover in the mountains, and even with mountain ridges nearby. I have seen very few outdoor situations/settings with the SporTrak Pro where it cannot find WAAS signals, just as I have seen very few outdoor settings where it cannot find at least 3 or 4 satellites for conventional GPS. Much of what I have written is also true for our $60 Explorist 100, but it is a bit slower and a bit less sensitive. I did note that the Explorist cound not find WAAS while I was in India, and this led me to conclude that the WAAS ground statinos and satellites were likely set up primarily for the USA or perhaps the Western Hemisphere... will have to read up on that topic someday on the web to find out the intended coverage area for WAAS...

 

My observation in the field is that a really accurate consumer-level GPSr such as the SporTrak Pro can yield an accuracy/repeatability within about 3 to 4 meters (if I allowed a hold-still settling time of at least 2-3 minutes), if not better. However, as other posters have pointed out, such tightness of accuracy is of little value if the cache hider took quick and sloppy measurements or used a less-than-accurate GPSr. So, while I appreciate the tight accuracy that our GPSr can yield when using WAAS and long averaging/settling times, I fully understand and accept that many caches may not really be located at the waypoint ground zero at all, but rather 50 or 100 or 150 feet away. And that is where I believe that using intuition and gut sense comes in... And, when I get really stuck in finding a cache, I just give up and ask the angels to lead me to it!

[+DaemonLee]

Thanks for everyone's help in this topic.