eTrex Vista - Area Calculations

[+kowtow]

I just bought an eTrex Vista and I've been pretty happy with it, but I must say the 'Area Calculation' feature is essentially worthless. Out of nearly 100 calculation attempts and two calls to Garmin customer service it has worked twice.

 

Symptoms: After pressing 'Start' for the Area Calculation, walking the area, then clicking 'Stop' it returns 0.00000 for the area (regardless of the selected units).

 

Garmin Solution:

#1 Do a master reset and let it sit out turned on for 30 min. acquiring satellites and try again.

 

#2 Ensure that you have no other tracks active on the map screen, because they will be taken into the area calculation. Make sure when you complete walking the area, you cross over the exact 'Start' point, by overlapping it by at least 3-4 feet.

 

Regardless of trying either solution the area calculation program fails to function even in a remotely useful way.

 

Again, I'm really happy with the Vista and I wouldn't have bought another brand of GPS even if the Vista didn't have the Area Calculation feature. It fits perfect on my road bike and on the dash. It's as small as my cell phone, which makes it easy to drop into my pocket. I'm impressed with how much you can tweak the look of the screens to suit your taste.

 

That said, I wish they would have left the 'Area Calculation' feature off the unit. It is frustrating to me (coming from a product design and development background) to understand how they could even incorporate such a poorly functioning feature such as the 'Area Calculator' into their product. It detracts from my image of Garmin being the quintessential leader of the consumer GPS market, because it shows a lack of design discipline, and/or a product that has been hastily brought to market. These factors are inclusive of some important design "tollgates" that have missed in this product development.

[jfitzpat]

Garmin #1 sounds like standard customer service operating procedure - ie, when in doubt, get the customer to a clean slate

 

Garmin #2 seems reasonable, it has to be some sort of closed polygon for a calculation

 

After reading your post, I tried carrying my Vista to Starbucks, then went the long way around the block on my way back to the office. The area calculation seemed correct.

 

So, I cleared the track and tried again, this time stopping part of the way around and got a zero. I suspect that the feature may be coded correctly, but your usage may exceed the limitations of the GPS sat system.

 

For example, if you are trying to measure the area of something with a section narrower than 40-50', EPE could be giving the unit a much different shape to work with than you expect. Or, if you are in an area of poor reception or sat. geo., 3-4' of overlap may not be enough to give the unit a closed track to work with.

 

-jjf

[+kowtow]

jjf,

 

You could be correct about the size of the area being smaller than what the GPS can handle. I'm sure that with a much larger area the EPE would probably have much less impact. Additionally I can see how reception could grossly affect a smaller measurement area as well.

 

It's still strange that it worked the first time I used it on an area 8'x40' but every subsequent time I tried to measure the same area it turned up zeros. Maybe I got lucky the first time and all the planets were in alignment, reception was great, solar flares were at a minimum and it was a minus tide.

 

I just wish that such limitations were noted up front. I'm going to generalize, but I think people would want this tool to provide a rough estimate of a lot size, or some other type of boundary measurement. If this is beyond the repeatable capability of the Vista, stating it with a brief disclaimer up front would suffice.

 

Thanks for your reply it definitely shines a little more light on some of the general limitations that I was taking for granted.

[+apersson850]

Make sure you just aren't running along the same road, with the "Lock on road" feature enabled. If so, you may be measuring the area that fits inside two lines, on top of each other. That area is indeed small. The "Lock on road" feature will force your position to be on the line that represents the road, even if you have some deviations from that line in the measured position. Hence, driving along one side of even a rather wide road, crossing the road and going back again along the other side, still returns the area "zero".

 

Otherwise, the EPE doesn't make much difference even for small areas, since it usually adds the same error at two places, that aren't very far apart.

 

One can set units for the area, which will round the area to zero, even if it isn't, really. There is also a bug, which Garmin has refused to fix, that displays some units incorrectly (by omitting one digit in the result).

 

Otherwise, the area calculation has worked fine for me.

 

Anders