Dead-reckoning animal movements in R: a reappraisal using Gundog.Tracks
byRichard M. Gunner, Mark D. Holton, D. Michael Scantlebury, Carlos M. Duarte, et.al
Gunner, R. M., Holton, M. D., Scantlebury, M. D., van Schalkwyk, L., English, H. M., Williams, H. J., Duarte, C.M., ... & Wilson, R. P. (2021). Dead-reckoning animal movements in R–A reappraisal using Gundog. Tracks.
Fine-scale data on animal position are increasingly enabling us to understand the details of animal movement ecology and dead-reckoning, a technique integrating motion sensor-derived information on heading and speed, can be used to reconstruct fine-scale movement paths at sub-second resolution, irrespective of the environment. On its own however, the dead-reckoning process is prone to cumulative errors, so that position estimates quickly become uncoupled from true location. Periodic ground-truthing with aligned location data (e.g., from global positioning technology) can correct for this drift between Verified Positions (VPs). We present step-by-step instructions for implementing Verified Position Correction (VPC) dead-reckoning in R using the tilt-compensated compass method, accompanied by the mathematical protocols underlying the code and improvements and extensions of this technique to reduce the trade-off between VPC rate and dead-reckoning accuracy. These protocols are all built into a user-friendly, fully annotated VPC dead-reckoning R function; Gundog.Tracks, with multi-functionality to reconstruct animal movement paths across terrestrial, aquatic, and aerial systems, provided within the Additional file 4 as well as online (GitHub).