Abstract
Due to developments in global navigation satellite systems (GNSS) and the miniaturization of their components, the usage of Global Positioning System (GPS) is no longer restricted to professional applications, but has become available in various consumer type devices, such as wristwatches. These commercial devices, however, were primarily designed for tracking activities in predominately urban settings and their accuracy has not been tested in forested areas. In this study, we present an assessment of the positional accuracy of a GPS watch (Ambit Peak 3, Suunto, Finland) under different forest cover types, seasons and meteorological conditions within the Whitehall Forest GPS Test Site located in Athens, Georgia, USA. As a standard of comparison, the performance of the GPS watch measurements was juxtaposed to that of a mapping-grade receiver (Juno T41, Trimble Inc., USA). In this study, we analyzed the differences between the determined and control positions using root-mean-square-error (RMSE), along with the distribution of observed positions through the standard deviational ellipse. The results suggest that the seasonal variations contributed to a statistically significant impact on the RMSE values for the GPS watch. However, there were no statistically significant differences in horizontal position accuracy by forest cover-type when using the GPS watch. Furthermore, no significant differences were found in horizontal position accuracy during the leaf-off period between the RMSE values for the GPS watch and those of the mapping-grade receiver. Lastly, the positional accuracies for both types of receivers were found to be weakly, but significantly correlated with fluctuations in air temperature and absolute humidity.
Highlights
Some discussions concerning the development of global navigation satellite systems (GNSS) occurred before the 1980s, their notable development began in earnest on the NAVSTAR Global Positioning System (GPS) (United States) and GLONASS (Russia) systems during the 1980s
We found a significant difference in the mean RMSE values between the leaf-on and leaf-off seasons when using the GPS watch
The key findings of this study were as follows: (1) the accuracy of the GPS watch was significantly affected by the season, but not by the cover type; (2) during the leaf-off season, the accuracy of the GPS watch did not differ significantly relative to the accuracy of the mapping-grade GNSS receiver; (3) the RMSE values of both GPS receivers had a significant but weakly positive correlation with air temperature and absolute humidity
Summary
Some discussions concerning the development of global navigation satellite systems (GNSS) occurred before the 1980s, their notable development began in earnest on the NAVSTAR GPS (United States) and GLONASS (Russia) systems during the 1980s. Static horizontal accuracy of GPS watch in different forest cover types recent years, there have been further developments by other entities, such as China’s BeiDou/ COMPASS and European Union’s GALILEO projects Each of these four systems provide publicly available signals, which hardware technology manufacturers can subsequently use to develop commercially available GNSS receivers. Many in the general public are beginning to use GPS watches to navigate or track their activities while exercising, without proper understanding of the impact that various meteorological conditions may have on GPS functionality It is uncertain whether the positional information derived from non-traditional types of GNSS receivers can serve as a reliable substitute in non-ideal circumstances, relative to the reliable information collected by traditional mapping-grade, which are often used to acquire sufficient quality positional information demanded by forest management or forestry research professionals [4]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
