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An alternative index of satellite telemetry location error

July 1, 1994

Existing indices of satellite telemetry error offer objective standards for censoring poor locations, but have drawbacks. Examining distances and relative directions between consecutive satellite telemetry locations, I developed an alternative error index, ξ, and compared its performance with that of the location quality index, NQ (Serv. Argos 1988). In controlled tests, ξ was more (P ≤ 0.005) effective for improving precision than was a threshold of NQ > 1. The ξ index also conferred greater control over the trade off between sample size and precision, making ξ more cost-effective than NQ. Performances of ξ and NQ were otherwise comparable. In field tests with bighorn sheep (Ovis canadensis), rejecting locations where ξ ≥ 1.5 km reduced (P < 0.001) longitudinal dispersion, the predominant error component. Longitudinal dispersion for these locations was less (P = 0.025) than for locations where NQ > 1 and 63% fewer data were censored, so that the extent of animals' movements was better indicated by using ξ rather than NQ. Because use of ξ may lead to underestimating the number of long-range, short-term forays (especially when the frequency of forays is high relative to sampling frequency), potential bias should be considered before using ξ. Nonetheless, ξ should be a useful alternative to NQ in many animal-tracking studies.

Publication Year 1994
Title An alternative index of satellite telemetry location error
DOI 10.2307/3809311
Authors Kim A. Keating
Publication Type Article
Publication Subtype Journal Article
Series Title Journal of Wildlife Management
Index ID 70129389
Record Source USGS Publications Warehouse