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Sorry Robert, I Can GPS In The Rain Quite Well
Water only makes the needles conductive, but that same water in a deciduous tree has a different effect.
It is where the conducting water is and the configuration of the water that is the problem.
A forest of aluminum Christmas trees has the same effect as does a chain link fence.
Paul in PA
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I agree with Kent. I also think there are surveyors using RTK that think they get the right answer EVERY time they get a fix.
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It Is The Needle Length And The Needle Array
The GPS signals have a wavelength on the order of 19 and 25 cm. Magic things happen electrically to antennas that are 1/2 or 1/4 the wavelength, so pine needles around 1 3/4 to 2 1/2 inches long or twice that would be the worst.
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It’s not your head, it’s the PINE Tree needles that are the problem.
oops.!! see above! agree with Bruce S. Don’t even think about it.
The only thing worse than a pine tree to RTK near is a large Concrete Power pole…I assume the metal reinforcements inside them are the problem. NEVER trust an observation around them.
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I consider every RTK shot to be wrong, but then I also consider every static location to be wrong. I was an early adoptee so maybe I’m jaded, but I would get a bad RTK fix almost every day back about 1995, I know there’s better error trapping now but I learned the very first day of using RTK about bad fixes (very happy I did learn about it and how to deal with it), they are more rare now but still………..
If you take that mindset you will be much better off. Open sky and no clutter is no guarantee of good results.
And don’t believe someone that says I used static so that shot is good, that’s not how it works………
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all good comments. mark this one down as solar interference.
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Paul…
I thought that we were on the same page.
I would say our annual precipitation here is no problem and our proximity to the Gulf and some of the largest wetland areas in the USA so you can GPS survey in the rain here too (bring plastic bags). Watch out for the thunder boomers because they will cause crazy i.e. unpredictable ionization and its effects.
Most of the oaks, sycamores etc drop their leaves. But the Live Oak do not.
I do not know if you ever saw a in Louisiana a Live Oak Growing…. If you did , you would know not to set a GPS station nearby.
Relative humidity is 98% currently which is pretty much normal here on days throughout the year.
There was a nice ground fog this morning since earlier in the week the temps went down to the teens at night but yesterday rose to 70°. Good GPS weather for here.
Here is another pine tree that you should avoid in doing GPS. It is located in Mandeville, La , ironic because some believe that Whitman wrote the Live Oak poem after a trip to Mandeville and witnessed the splendid Live Oaks and the Spanish Moss hanging from the boughs.
Can you identify it? No it is not a longleaf, loblolly or shortleaf pine -
:good: I agree Mark, there are simply some units that are better, hard for average user to extensively test ALL candidates prior to purchase and so buyer beware!
Today I would seriously consider space weather as a contributing factor however.
SHG
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Paul…
Looks like a Cypress
A wet cedar grove cam actually shut down any GPS.
The pines around here have needles that are the right length to mess with the wavelength and will disrupt short setups.
A tall HI and long multiple setups will get a usable solution under dry conditions.
0.02
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I always do a static observation on questionable shots, but I use a base and rover, hiper lite + with 4mb ram. I guess you could do it with a network setup like yours, if you have storage memory on your receiver, and cors stations are close enough. When it fixes, I will store it and stake out the stored point for comparison. Opus-RS might be helpful, also, but a short observation usually won’t work very well under canopy or in marginal areas.
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Thanks, everybody! I picked up some gems while reading through the comments. I will incorporate many of these in my normal operations from now on. I do about half of my work with base and rover, and the other half with my cellular network rover.
The Okolona CORS station near my house was installed by the National Weather Service to measure moisture in the atmosphere. At last check, it was no longer operating.:-/
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Stephen is correct. Cell Tower
Stephen was correct. It is a cell tower. Concrete trunk and limbs are steel and leaves are aluminum.
I wonder why it doesn’t cause interference. It was put up about 15 years ago.http://www.waymarking.com/waymarks/WM4CVY_Mandevilles_Disguised_Cell_Tower
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Concrete Power Pole
It is the rectangular array of internal rebar (possibly wire mesh) that can give more problems than a steel pipe tower.
That cell tower has much fewer antenna than the ones I’ve seen on the Garden State Parkway, usually at least three tiers. In any event, a single tree, real or imagined, does not a forest make.
Paul in PA
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:good: :good: :good:
I don’t even waste time hoping when a pine tree is involved. It is a crap shoot or I need so many multiple checks that I’m better off switching to total station.
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Pine trees
We might find a few under 30-feet high that were intentionally planted in yards. Other than that, the only ones we see have Christmas decorations on them somewhere inside the house.
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This thread has some good stuff in it. Even Kent has a few gems.
Nate
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Yeah, I knew trees were bad but I didn’t know pine trees were especially bad.
I’ve been burned on a group of about 20 points with a bad fix once so far and I’ve tried keeping a closer eye on the RMS stats since then, but I’ve realized there is only so much babysitting I can do before I may as well break out the robot.
It’ll be interesting to see how the technology improves over the coming years.
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