Description of SiteData

The SiteData.rda file contains data.frame SiteData with the following variables:

• Survey: A single flight conducted using a UAV to collect data over a designated area. A total of 31 survey flights were conducted in this study.

• Study_area: A specific geographic location selected for conducting surveys. For this study, four sampling areas were selected: Haugen, Rå, Sprakehaug, and Søre Bjørkum.

• Route: A predetermined flight path followed by the UAV during a survey. In this study, each sampling area contained between three and five routes, and each route was surveyed between one and three times.

• Month: The month during which a survey was conducted (March or April).

• Date: The specific date a survey was conducted (R Date format).

• Flight_Altitude: Programmed flight altitude above ground in meters, based on the digital elevation model.

• Focal_image: Unique identifier for the focal image constituting the Site. All focal images are non-overlapping with other focal images from the same survey.

• Site: Site number within Survey, numbered consecutively from 1 within each Survey.

• File: File name for the Folcal image. Each file name corresponds to a raster image used for extracting information such as mean elevation, distance to the field, etc. from a Digital Elevation Model (DEM) (see variables below).

• Weather: The weather conditions during a survey as noted by Yr.no and confirmed by observations, such as clear, mostly clear, mostly overcast, mostly sunny, overcast, slightly overcast, or sunny.

• Temperature_C: The temperature (in degrees Celsius) at the end of a survey.

• Snow: Whether the survey area was covered with snow during the survey (yes or no). A survey area was considered snow-covered if more than 50% of the aerial images displayed snow-covered surfaces.

• Area: The total area (in square meters) covered by a site within a focal image.

• mean_x: The mean UTM zone 33V x-coordinate (east) of all pixels within a focal image.

• mean_y: The mean UTM zone 33V y-coordinate (north) of all pixels within a focal image.

• elevation_at_mean_pos: The elevation at the average east (x) and north (y) UTM coordinate of the site, derived from a DEM.

• mean_elevation: The average elevation (in meters above sea level) of a site, calculated as the mean of all elevation values within the site, derived from a DEM.

• min_elevation: The lowest elevation (in meters above sea level) within the site, derived from a DEM.

• max_elevation: The highest elevation (in meters above sea level) within the site, derived from a DEM.

• proportion_no_field: The proportion of the site that does not consist of fields. Calculated as the area of non-field land cover (e.g., forest, water, bare ground) divided by the total area of the site, derived from a polygon file.

• field_dist_at_mean_pos: The distance (in meters) from the average east (x) and north (y) UTM coordinate of the site to the nearest field, derived from a DEM and a habitat polygon file.

• mean_field_dist: The average distance (in meters) from all points within a site to the nearest field, calculated as the mean of all distance values within the site, derived from a DEM and a habitat polygon file.

• min_field_dist: The shortest distance (in meters) from any point within a site to the nearest field, derived from a DEM and a habitat polygon file.

• max_field_dist: The longest distance (in meters) from any point within a site to the nearest field, derived from a DEM and a habitat polygon file.

• proportion_forest: The proportion of a site that consists of forested land, calculated as the area of forest cover divided by the total area of the site, derived from a habitat polygon file.

• forest_dist_at_mean_pos: The distance (in meters) from the average east (x) and north (y) UTM coordinate of a site to the nearest forested area, derived from a DEM and a habitat polygon file.

• mean_forest_dist: The average distance (in meters) from all points within a site to the nearest forested area, calculated as the mean of all distance values within the site, derived from a DEM and a habitat polygon file.

• min_forest_dist: The shortest distance (in meters) from any point within a site to the nearest forested area, derived from a DEM and a habitat polygon file.

• max_forest_dist: The longest distance (in meters) from any point within a site to the nearest forested area, derived from a DEM and a habitat polygon file.

• aspect_deg: The average compass direction (in degrees) of the slope within a site, calculated as the mean of all aspect values within the site, derived from a DEM. Aspect is measured as degree north from 0° to 360°, where 0° represents north, 90° represents east, 180° represents south, and 270° represents west.

• slope_deg: The average steepness (in degrees) of the terrain within a site, calculated as the mean of all slope values within the site, derived from a DEM. Slope represents the angle between the ground surface and a horizontal plane, with 0° indicating flat terrain and higher values indicating steeper slopes.

• n_both: The number of red deer detected by both observer 1 and observer 2 within the site.

• n_only_ab: The number of red deer detected only by observer 1 within the site.

• n_only_jb: The number of red deer detected only by observer 2 within the site.