GPS reception under pine trees

[Guest CharlieP]

I have noticed that my GPS often has reception problems under pine trees, and other geocachers have the same problem at those same cache locations here in north Georgia (USA). I remember someone telling me that a radio frequency with a wavelength about the same as the length of the pine needles will be severely weakened passing through the tree top. I computed the wavelength of the GPS signal to be about 7.5 inches, which is about the length of our typical pine needle. Can anyone confirm my math and/or verify this theory?

 

CharlieP

[Guest Kerry]

The L1 signal has a wavelength of about 19cm (close enough to 7.5") but can't offer any comments on the pine needle theory.

 

Cheers, Kerry.

[Guest Forester]

Any tree canopy greatly effects the GPS signal. A double or triple layer will very nearly shut you down, if its raining, then it's even worse.

[Guest lee_rimar]

t loses lock.

 

But I've come to realize this is an exceptional handheld unit. I recently bought (and returned) a much more expensive, newer model and found it didn't perform neary as well.

[Guest EraSeek]

Forester has mentioned in the past that a WET canopy will greatly inhibit a signal. I'm wondering if sap content also makes a difference. Pine probably has a greater sap content then many other trees.

[Guest Kerry]

quote:

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Originally posted by EraSeek:

Forester has mentioned in the past that a WET canopy will greatly inhibit a signal. I'm wondering if sap content also makes a difference. Pine probably has a greater sap content then many other trees.

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A wet canopy has all to do with Multi-path and acts like a disco crystal ball.

 

Really don't think sap would affects things much more than the obstructions themselves.

 

Cheers, Kerry.