Influence of topographic position on GPS collar performance in a mountainous region
WEN Hui, YUAN Xuelin, CAO Yindi, REN Guopeng, HUANG Zhipang, XIAO Wen
2022, 42(2):
204-210.
DOI: 10.16829/j.slxb.150594
Asbtract
(
)
HTML
(
)
PDF (5001KB)
(
)
References |
Related Articles |
Metrics
Global Positioning System (GPS) collars have been widely used to monitor the movements of large mammals in the field.However,data collected by GPS collars are subject to two types of error:one is the location error,and another is the missing data bias.Therefore,the positioning performance of GPS collars should be evaluated and accounted for when designing relevant ecological studies such as habitat selection.To test the hypothesis that the positioning performance of the GPS collar is better on mountain ridges than that in valleys,we set two stationary points on the ridge and another two stationary points in the valley of Cangshan Mountain,Dali,Yunnan.All these four points were set up at the same altitude above sea level (approximate 2 600 m).In addition,to measure the performance of GPS collars under ideal conditions,we also placed two GPS collars over an open site.The positioning performance varied according to different topographic positions.First,the fix success rate ranged from 21.7% to 21.9% in the two valley points,increased to 29.2%-37.8% on the ridge points,and reached 79.2% in the open site.Second,the location errors of the valley points were much larger than those of the ridge points.The 50% circular error probable (CEP) of the 3D fixes were 21 m and 28 m at the valley points,13 m and 20 m at the ridge points,and 5 m at the open site.However,the 90% CEP of the 3D fixes were 843 m and 2 837 m at the valley points,95 m and 690 m at the ridge points,14 m at the open site.Third,the precision of GPS collars in the valley was 56.5 m and 106.3 m,while on the ridge of the mountain it was 21.6 m and 40.9 m,and only 7.3 m in the open site.Our results suggest that the performance of the GPS collar was severely influenced by the rugged terrain.Thus,it is essential to evaluate both the missing data bias and the location error of GPS fixes in mountainous regions before performing ecological analysis with the obtained GPS data.