Lost Gps Signal

I want to map out a mountain bike trail with lots of trees and valleys. I can't get a signal with my GPS. Any suggestions to boost the range?

trialex10 years ago
Do you need a map of where you ACTUALLY went, or would it be OK to use something like Gmap-Pedometer
trebuchet0310 years ago
Get your receiver above the trees and valleys :/ Unfortunately, GPS is line of sight...