+Siberian Cacher Posted March 12, 2003 Posted March 12, 2003 I've heard that tree "canopies" can alter the received signal. Is this pertaining to the denisty of the trees or the amount of leaves or is either even a concern? Quote
+Renegade Knight Posted March 12, 2003 Posted March 12, 2003 Both. The canopy contains water, water blocks signals. If you can't see the sky, odds are neigher can your GPS. "Canyons" bounce signals. Thus being near a rock face, building, bridge can mess up your signals. I've noticed spots here where the tree's have no leaves due to winter where my signal is still bad. They are 'dense' trees and close together. In the summer the signal will flat out dissapear. To check out the water thing, sometimes you can get reception in your house (but not your basement) without the line of sight. As the post below says, more stuff in the way is also bad. The worst I've ever seen for signal problms was a cliff on three sides with dense canopy down below where the cache was at. Wherever you go there you are. Quote
+flask Posted March 12, 2003 Posted March 12, 2003 it has to do with the amount of stuff that blocks your receiver's view of the sky. the more stuff, the worse your reception will be. it doesn't matter if you get to camp at one or at six. dinner is still at six. Quote
+Searching_ut Posted March 13, 2003 Posted March 13, 2003 Type of tree cover, moisture content, desity, all contribute to reception problems. In many of the western states, you often notice a big difference hiking the same trail, with basically the same thickness of tree cover, but very different moisture contents as the summer goes on without rain for months sometimes. Quote
dsandbro Posted March 13, 2003 Posted March 13, 2003 There has been research papers on this topic. In theory, conifers block signal more than broadleaf, all other factors being equal. In actual on the ground experience most GPS users report the opposite. Canopy density and foliar moisture content play a role. Liquid water on the leaves after a rainstorm also affects signal. These are too variable and dynamic to come up with any formula or algorithm. Just use the rule of thumb if you cannot see the sky the satellites cannot see you. ======================================== Friends don't let Friends geocache drunk. Quote
Kerry. Posted March 13, 2003 Posted March 13, 2003 Lots of variables and generally unknowns especially with wet trees as it's not only possibly an obstruction but also can be an interference, with respect multipath as wet trees can tend to act like big mirror balls. Cheers, Kerry. I never get lost everybody keeps telling me where to go Quote
+georgeandmary Posted March 13, 2003 Posted March 13, 2003 For some unknown reason, Eucalyptus trees really screw with my reception. More so that other trees I've encountered. Don't know why. george Pedal until your legs cramp up and then pedal some more. Quote
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