What is WAAS

[Team Venom]

Sorry but even with all my army PLGR,GPSr,etc training i can find no reference…so im asking the knowledge pool!
All the new GPSr i see are WAAS so what is it and what does it do? FYI i use a older EAGLE GPSr…please don’t laugh tooo hard, it’s served me faithfuly for many years and many miles in the service. Is it still a good unit yet, or should i consider a new one? I do find the caches, so i figure it’s doing what it should…ok i be quiet now

[Todd Bloomingdale]

This is directly from the Garmin website. Hope this explains it well enough. I have mine activated on my Garmin GPS V and it does bring the accuracy down to the feet if it gets the WAAS signal. Some ares wont get the signals so you only get the satalite signal. Hope this helps
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You’ve heard the term WAAS, seen it on packaging and ads for Garmin® products, and maybe even know it stands for Wide Area Augmentation System. 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.

The origins of WAAS

The Federal Aviation Administration (FAA) and the Department of Transportation (DOT) are developing the WAAS program for use in precision flight approaches. Currently, GPS alone does not meet the FAA’s navigation requirements for accuracy, integrity, and availability. WAAS corrects for GPS signal errors caused by ionospheric disturbances, timing, and satellite orbit errors, and it provides vital integrity information regarding the health of each GPS satellite.

How it Works

WAAS consists of approximately 25 ground reference stations positioned across the United States that monitor GPS satellite data. Two master stations, located on either coast, collect data from the reference stations and create a GPS correction message. This correction accounts for GPS satellite orbit and clock drift plus signal delays caused by the atmosphere and ionosphere. The corrected differential message is then broadcast through one of two geostationary satellites, or satellites with a fixed position over the equator. The information is compatible with the basic GPS signal structure, which means any WAAS-enabled GPS receiver can read the signal.

Who benefits from WAAS?

Currently, WAAS satellite coverage is only available in North America. There are no ground reference stations in South America, so even though GPS users there can receive WAAS, the signal has not been corrected and thus would not improve the accuracy of their unit. For some users in the U.S., the position of the satellites over the equator makes it difficult to receive the signals when trees or mountains obstruct the view of the horizon. WAAS signal reception is ideal for open land and marine applications. WAAS provides extended coverage both inland and offshore compared to the land-based DGPS (differential GPS) system. Another benefit of WAAS is that it does not require additional receiving equipment, while DGPS does.

Other governments are developing similar satellite-based differential systems. In Asia, it’s the Japanese Multi-Functional Satellite Augmentation System (MSAS), while Europe has the Euro Geostationary Navigation Overlay Service (EGNOS). Eventually, GPS users around the world will have access to precise position data using these and other compatible systems.

It just keeps getting better

100 meters: Accuracy of the original GPS system, which was subject to accuracy degradation under the government-imposed Selective Availability (SA) program.
15 meters: Typical GPS position accuracy without SA.
3-5 meters: Typical differential GPS (DGPS) position accuracy.
< 3 meters: Typical WAAS position accuracy.

[Cathunter]

My experience is that more often than not, you will not get WAAS reception in the woods.

If you view the satellite screen on a Garmin GPSr, satellites appearing as numbers higher than 32 are actually referencing the satellites that provide WAAS corrections. I believe numbers 35 and 47 are the only ones that can be recieved in the U.S.

A Garmin unit uses one or two of it’s channels strictly for hunting WAAS data. I keep WAAS turned OFF on my unit, as not only do I very seldomly get reception, but it also seems to greatly improve battery life.

Regardless, I would tend to believe that the improvements and added functions of the newer units would make replacing yours a popular decision.

[Ray]

Our experience with WAAS indicates that it helps to gobble up battery capacity. This requires more frequent battery changing and greater rates of burning calories on the trail. Thus helping to shed unwanted pounds or allow for more frequent DQ stops. One might get the same effect from mailing a SASE weekly.

[Ootek]

I had been disappointed with the performance of our GPSMap 76S. Even knowing that receivers are flaky, especially approaching the destination, I felt ours was worse than it should be. I researched a bit and found that having WAAS enabled but not receiving it can cause the receiver to be less accurate. The two satellites Cathunter speaks of are low on the SE and SW horizon. The chances of getting them in our part of the country are slim. so, I turned off WAAS.

I reduced the speed at which the electronic compass kicks in to below 1 mph and also discovered, after reading the manual, that the compass needs to be recalibrated after every battery change. I disabled Battery Saver mode, too, so the unit updates once per second instead of once every 5 seconds.

It seems that, since doing this, the receiver fluctuates less. I guess we’ll just have to go caching more to test the theory.

[Miata]

How does one recalibrate the compass? I have never found the option on any of my Garmin units (GPS II, GPS III, and GPS V)

quote:

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Originally posted by Ootek:
I had been disappointed with the performance of our GPSMap 76S. Even knowing that receivers are flaky, especially approaching the destination, I felt ours was worse than it should be. I researched a bit and found that having WAAS enabled but not receiving it can cause the receiver to be less accurate. The two satellites Cathunter speaks of are low on the SE and SW horizon. The chances of getting them in our part of the country are slim. so, I turned off WAAS.

I reduced the speed at which the electronic compass kicks in to below 1 mph and also discovered, after reading the manual, that the compass needs to be recalibrated after every battery change. I disabled Battery Saver mode, too, so the unit updates once per second instead of once every 5 seconds.

It seems that, since doing this, the receiver fluctuates less. I guess we’ll just have to go caching more to test the theory.

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[sbukosky]

Everyone has an opinion so might as well toss mine in. Getting WAAS lock can be tough. I’ve experimented with it in the woods and fields and find that if a can do a waypoint average with WAAS lock, I can come closer to that exact spot days later. So, I believe that if when placing a cache, if you can do a waypoint average using WAAS, that is where it is most useful. Otherwise for the hunters of the cache, use of WAAS is of small, if any, benefit.

I’m a person who likes accuracy. When the surveyor quality GPS come down to a reasonable price, I’ll buy one. Maybe we can have something like a Golfing ”closest to the tee” type of accuracy contest.

[Team Venom]

Wow!!! almost too much information…I do have the DGPS setup (extra gear)on mine and the earlier post says 3-5 meters…thats about ave. for me…sometimes i get right on the co-ord’s first time but most time im close…3-5 meters

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Team Venom
The Pike Family

[Ootek]

Miata, I don’t think the Garmin II, III or V offer an electronic compass feature. The 76S, 76CS and 60CS do, for example. Calibration is an option in the compass page menu and involves selecting the option and rotating the receiver on a level surface through two full turns.

Ootek

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