Attn: eTrex Legend owners

[etalon91]

With WAAS enabled, what is the average accuracy you get with you Legend (in meters).

 

When you search for caches, is the accuracy out a great deal? compared to what the coords were listed?

 

The reason I'm asking is that I have been testing my unit on trails (open trails), with trees on either side, and the accuracy will fluctuate from 11 meters all the way to 30 meters? Dpes your unit do the same thing? Will I have a little trouble finding a cache if I'm out that much?

 

Thanks for your input.

[SergZak]

You should be aware that having WAAS enabled is not always a good thing. A very clear view or the east/west sky is required for WAAS corrections & I doubt that would be the case on a trail with trees on either side. Having WAAS enabled also uses up two of the twelve satellites that your unit has available for operation. If the two WAAS satellites are not visible to the unit, they are pretty much useless. In this case, it's better to have WAAS disabled so that two more non-WAAS satellites can be used for additional/better positioning. WAAS also requires more processing power and you will see slower GPS operations such as screen redraws, especially if the unit is continuously searching for the WAAS satellites. In my area (Los Angeles, CA), I don't use it one bit...but it is very useable when down on the coast/on the water where the view is unobstructed. This is the case with all WAAS enabled units but the eTrex line (Legend, Summit, Vista) are more prone to problems locking/holding onto WASS satellites because of their less sensitive patch antenna (compared to the quad-helix antenna of other Garmin and Magellan units).

[+Searching_ut]

If you're looking at the EPE figure that the receiver is reporting, it may or may not be of much use. It's more or less a wild guess made by the software in your unit. I've found that in conditions with unobstructed views of the sky, the EPE is often in the ballpark. Get in a tree filled canyon, and your actual error is generally quite a bit more that what the receiver is telling you it is.

 

That said, in clear sky's I generally get accuracy of about 3 meters based on real measurements, not the EPE. Without WAAS, in trees or canyons I'm generally withing 10 to 15 meters. Errors of 50 meters or more do happen in reception problem areas however.

 

I've found the Legend guides me to caches fairly well.

 

For some of my ramblings, about the Legend amoungst other receivers check out:

 

http://home.sprynet.com/~searching_ut/index.htm

[etalon91]

Thanks for your replies, much appreciated.

 

You answered another question I had

 

When I locked a position, I had decent accuracy, and I only had 10 satellites listed in my unit. I guess when WAAS is enabled it will only look at 10? instead of the normal 12.

 

I will click on the search button immediately.

 

Thanks again.

[SergZak]

quote:

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When I locked a position, I had decent accuracy, and I only had 10 satellites listed in my unit. I guess when WAAS is enabled it will only look at 10? instead of the normal 12.

 

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It will see however many satellites are visible in the sky at that point in time (but not always). Sometimes there are only 5 or 6 visible and other times (not very often) there will be 12. Look at it this way...you have a good chance of getting/using two more visible satellites than you already have if you have WAAS disabled.