Using differential GPS for forest traverse surveys

Abstract

This report documents the accuracy and efficiency of differential GPS (DGPS) when it is applied in forest environments. The report contains research results obtained from using DGPS for forest-stand boundary surveys conducted in hardwood forests in a mountainous region. Reported also is the result of a cost-effectiveness analysis that contrasts the satellite-based DGPS positioning and the conventional land-based compass-and-chain surveys. The study found that (1) both forest canopy and undulating terrain in mountainous regions would exert a definite effect on DGPS traverse surveys but neither would reduce stand area determination accuracy; (2) in general, static DGPS was more accurate but less productive than the kinematic DGPS when accuracy and cost were weighted equally; (3) inaccurate two-dimensional position determinations degraded positioning accuracy in either the kinematic or static positioning mode; and (4) kinematic DGPS traverse was a cost-effective survey technique capable of achieving closer forest stand area approximation than the compass-and-chain traverse.