Wintec WBT-100 w/ BeeLineGPS (PPC) jumps around so much I can't find anything. Which BT GPS is the best?

[+zimmer62]

I guess my question is, is the WBT-100 bad for geocaching? It works great for driving, but I'm concerned that it is not accurate enough when walking around.

 

It'll show I'm 100ft away, and then 5ft, and then 75ft etc. when I'm standing still. I've actaully been standing 3ft from a cache before not knowing it, becuase my GPS was jumping around showing I was still 75ft or 20ft or 50ft or 200ft or 17ft or 43ft away. (you get the idea)

 

Is this kind of accuracy normal? I sure would like to be able to narrow it down to small enough area that I could actully find something in a reasonable time.

 

When I'm standing still, the GPS coords are not, and that pretty much tells me I shouldn't be using this to place caches since no one else will ever be able to find them if I publish my seemingly ramdom numbers.

 

If it's the GPS unit itself, I'll replace it with another bluetooth gps... And that brings me to my final topic.

 

What Bluetooth GPS receiver to buy for the most accurate results when walking. I remember a post on here showing a comparison of someone walking through the city, and the map showed near perfect result for one type of gps chip... What is the current status of the most desirable bluetooth gps unit for geocachers.

 

Thanks!

 

Joe Zimmerman

[+Steel City Seekers]

It sounds like your receiver has a thing called "static navigation" disabled. I admittedly have a limited understanding of static navigation, but I think it goes something like this. When static navigation is enabled and you are below a certain speed, the receiver freezes, discontinues using new GPS data, and shows you in one spot. It only accurately updates itself when it is above a certain speed threshhold. When you're using a receiver that does not have static navigation enabled and you're standing still, the receiver somehow (this is where it's a bit fuzzy for me) gets an increased number of inaccurate positions. This makes your reported position jump all around. I think they do this because they were primarily designed for use in a car rather than walking around.

 

I know how you feel, though. I have a BT receiver with a Sirf II chip that apparently did not have static navigation enabled. I tried to find a cache with it and it was like hitting my head on a wall. It had me going sometimes a quarter mile in different directions. I have no clue where that cache was! I also have a BT receiver with a SirfIII chip that has static navigation enabled. It is much more reliable. The only catch is that you have to move over the minimum speed, which isn't too much of a problem given that is about a normal walking pace.

 

With regard to the Wintec, it uses a chip I've never heard of: the u-Nav + iTrax, 3rd generation. It seems to me that the static navigation is not enabled on this receiver based on the discussion (see the con in particular) in this review:

 

http://www.mobilitysite.com/articles/link.php?id=352

 

For some more discussion about static navigation and some software and procedures you might be able to use to enable static navigation on your receiver, spend some time reading this article paying particular attention to the fourth section on static navigation:

 

http://www.gpspassion.com/forumsen/topic.asp?TOPIC_ID=25575

 

The potential problem is that the programs and fixes in the article are, I think, specifically for SirfIII receivers.

 

If I were you, I'd try some of the suggestions in the gpspassion article before scrapping the receiver and investing in a new one.

 

If you end up going for a new receiver, I'd suggest one of the SirfIII models. There are a zillion of them out there, they seem to be customizeable using the above link, and I think most of them come with static navigation already enabled.

 

Good Luck.

 

Edit: In re-reading the gpspassion article, I got it totally backwards. You want static navigation to be off for pedestrian use. Sorry -- reverse everything I said above. Also, please note that the software is for a PC, but there is a post after the article that references a Pocket PC application you can use to change settings. Again, it might be specifically for a SirfIII chip, but it might work or maybe you can google for something similar for the Wintec's chip.

Edited February 23, 2007 by Steel City Seekers

[+GPSlug]

Is this happening in a fully open sky or only with obstructions around? Maybe this receiver is really bad with multipath.

 

Also something you can try is playing with the position filtering that BeelineGPS does. If both the receiver and BeelineGPS are doing filtering, you can get a pretty strong slingshot effect. If neither the receiver nor BeelineGPS are filtering, it could be pretty noisy. So if it's on now, try turning it off. Or vice versa.

[+zimmer62]

Is this happening in a fully open sky or only with obstructions around? Maybe this receiver is really bad with multipath.

 

It seems to happen both ways... more so if there is stuff around... It's getting me 75% of the way to the cache, but the last bit is nearly impossible most times.

 

I'm going to see if I can find something about the static navigation.

[+RumJungle]

I'm going to see if I can find something about the static navigation.

 

Static navigation is specific to the SiRF GPS chip set. I believe that the WBT-100 uses the iTrax GPS chip set which is very different from the SiRF GPS chip set. I found this review on the GPS receiver.