Accuracy and precision of GPS receivers under forest canopies in a mountainous environment

  • R. Valbuena Research Group for Sustainable Management (Tecnatur). Faculty of Forestry. Universidad Politécnica de Madrid (UPM). Ciudad Universitaria s.n. 28040 Madrid
  • F. Mauro Research Group for Sustainable Management (Tecnatur). Faculty of Forestry. Universidad Politécnica de Madrid (UPM). Ciudad Universitaria s.n. 28040 Madrid
  • R. Rodriguez-Solano Research Group for Sustainable Management (Tecnatur). Faculty of Forestry. Universidad Politécnica de Madrid (UPM). Ciudad Universitaria s.n. 28040 Madrid
  • J. A. Manzanera Research Group for Sustainable Management (Tecnatur). Faculty of Forestry. Universidad Politécnica de Madrid (UPM). Ciudad Universitaria s.n. 28040 Madrid
Keywords: forest inventory, georeferencing, global navigation satellite system (GNSS) (GLONASS), optimum observing time

Abstract

Georeferencing field plots by means of GPS/GLONASS techniques is becoming compulsory for many applications concerning forest management and inventory. True coordinates obtained in a total station traverse were compared against GPS/GLONASS occupations computed from one navigation-grade and three survey-grade receivers. Records were taken under a high Pinus sylvestris L. forest canopy situated in a mountainous area in central Spain. The horizontal component of the absolute error was a better descriptor of the performance of GPS/GLONASS receivers compared to the precision computed by the proprietary software. The vertical component of absolute error also failed to show the effects revealed when the horizontal one was studied. These differences might be critical for applications involving high-demanding surveys, in which a comparison against a terrestrially surveyed ground truth is still mandatory for accuracy assessment in forested mountainous areas. Moreover, a comparison of diverse Differential GPS/GLONASS techniques showed that the effect of lengthening the baseline and lowering the logging rate was not significant in this study. Differences among methods and receivers were only observed for recording periods between 5 and 15 minutes. The hand-held receiver was inappropriate for plot establishment due to its inaccuracy and a low rate of fixed solutions, though it may be used for forest campaigns tolerating low precision or permitting the employment of periods of 20 minutes or longer for plot mensuration.

Downloads

Download data is not yet available.
How to Cite
Valbuena, R., Mauro, F., Rodriguez-Solano, R., & Manzanera, J. A. (1). Accuracy and precision of GPS receivers under forest canopies in a mountainous environment. Spanish Journal of Agricultural Research, 8(4), 1047-1057. https://doi.org/10.5424/sjar/2010084-1242
Section
Agricultural environment and ecology