An example GPS track of a stork niclas and an example Digital Elevation Model dem are included in the package. The DEM is a snippet from the SRTM 90m Digital Elevation Database v4.1 from CGIAR-CSI and the stork track is a subset of the data in the study LifeTrack White Stork SWGermany 2014-2017 (Movebank Study ID 21231406) from the Movebank Data Repository.
The area covered by the test data is the Swiss midland. The example track is a data.frame with coordinates in x, y and z. The x and y coordinates are in the CH1903+ / LV95 (EPSG:2056) reference system.
head(niclas)
#> x y z
#> 1 2556476 1188336 1283.736
#> 2 2558565 1189297 1359.580
#> 3 2560477 1189861 1369.713
#> 4 2562431 1190668 1391.752
#> 5 2563809 1190657 1806.566
#> 6 2567940 1192930 1764.062The DEM is a rasterLayer of the raster package, it’s Coordinate Reference System (CRS) is also CH1903+ / LV95. The stork flies from southwest to northeast, GPS fixes are collected every 15 minutes.
dem
#> class : RasterLayer
#> dimensions : 175, 501, 87675 (nrow, ncol, ncell)
#> resolution : 251.2, 370.8 (x, y)
#> extent : 2543252, 2669103, 1177108, 1241998 (xmin, xmax, ymin, ymax)
#> crs : +init=epsg:2056 +proj=somerc +lat_0=46.95240555555556 +lon_0=7.439583333333333 +k_0=1 +x_0=2600000 +y_0=1200000 +ellps=bessel +towgs84=674.374,15.056,405.346,0,0,0,0 +units=m +no_defs
#> source : memory
#> names : srtm_38_03
#> values : 374.3316, 2602.137 (min, max)