Behavior of GPS Signal Interruption Probability under Tree Canopies in Different Forest Conditions

Abstract

Global Positioning System (GPS) surveys were conducted over one year in four different forest environments in order to observe interactions between signal interruption probability (SIP), canopy opening index, observation period, number of available satellites and positional dilution of precision (PDOP). SIP showed larger correlation to positional errors than canopy opening index or PDOP, both horizontally and vertically, which contrast with some previous studies. An observation period of up to 15 minutes provided acceptable positional accuracy in correlation with SIP. Through indexes like SIP, canopy structure itself and signal behavior can provide a better understanding of accuracy in forestry.

Keywords:

• GPS
• survey
• canopy opening
• signal interruption probability
• accuracy