Tools to read, clean and standardise GNSS (Global Navigation
Satellite System) streams recorded by sports watches and similar devices,
with a focus on trail and mountain running. The pipeline reads GPX files,
applies a naming convention, sanitises coordinates (Kalman, LOESS,
Gaussian kernel or Savitzky-Golay smoothing, and red flags for implausible
readings), resamples the trajectory to a uniform spatial resolution derived
from the Nyquist criterion, and replaces elevation with values from a
Digital Elevation Model. Derived measures include speed, slope, elevation
gain and kilometre-effort, Tobler hiking function parameters fitted by
quantile regression, comparison between streams, detection of passes
along a route and map matching to a known reference trail by dynamic
programming. Methods follow Sanchez and Villena (2020)