[Ham-Mac] Rayming TN-200

[Dan Blasberg]

Chris,

I live down the road in College Park, send me an e-mail off list and i 
can see about coming up and give you a hand with my Garmin.


Dan Blasberg
KA8YPY

On Apr 30, 2004, at 11:22 AM, Chris Smolinski wrote:

>>> Anyone know what the accuracy of this beast is? I need to find some 
>>> property markers that are way back in the woods, in brush and 
>>> thorns. Could this or a hand held GPS unit get me to within say 5 or 
>>> 10 feet so that I might be able to find the marker?
>>
>>
>> My Garmin GPS V never says the accuracy is better than 16 feet, even 
>> with WAAS enabled and 6 birds accessed. 5 feet is a real push, and if 
>> you're in the woods, surrounded by trees, your results will suffer as 
>> reception diminishes. But, walking in a circle, with the compass 
>> display, you can zero in on it pretty well.
>
> Some googling for WAAS claims the accuracy approaches an RMS value of 
> 1 meter, that's about 2 meters or 6 feet 95% of the time, as you 
> average for a long time (time = an three hours or so). Here's the 
> site: http://users.erols.com/dlwilson/gpswaas.htm
>
> I would guess that with a USB unit, I could average for as long as I'd 
> like by taking readings and averaging them myself (if my iBook 
> batteries hold out that long!), do the handheld units allow you to set 
> long averaging periods?
>
>
>> If you've ever tried Geocaching, you know that it's pretty tough to 
>> pinpoint a lat/lon position. Think about it -- your arms outstretched 
>> span is about 6 feet. At least you know the markers are on the ground 
>> and not hidden in a hollow tree.
>
> Sounds like an interesting hobby. Someone mentioned that he used to do 
> work for the USGS finding markers, and used GPS to get close (back in 
> the days before WAAS) and then just poke around in the brush to find 
> the marker, which got me to thinking I could use it for my needs.
>
>> Wear long pants and gloves.
>
> Oh definitely, especially as I only need to approach with 2 or 3 
> meters of poison ivy to get a rash, it seems. This would be a better 
> exercise to undertake in the winter, when that stuff is all dead.
>
> To add to the challenge, there's a small stream back near the property 
> line as well. Supposedly there is a concrete marker back there which 
> will pin down at least one corner. I still need to figure out if I can 
> convert a location on the map to some sort of absolute lat/lon 
> position. I'm assuming the marker is still there, they have a habit of 
> getting [re]moved by kids. :-(
>
> To keep somewhat related to the list - it's all so I can install a 
> very long longwire antenna ;-)
>
> -- 
>
> ---
> Chris Smolinski
> Black Cat Systems
> http://www.blackcatsystems.com
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