Check photo coverage of an AOI by group

Builds footprint polygons for each photo, intersects with the AOI, and reports percent coverage grouped by a column.

Usage

fly_coverage(photos_sf, aoi_sf, by = "photo_year", dem = NULL)

Arguments

photos_sf

An sf point object with a scale column. Geometry must be POINT — the ground footprint is estimated from a centroid, so passing footprints back in is refused rather than coerced.

aoi_sf

An sf polygon to check coverage against.

by

Column name to group by (default "photo_year").

dem

Optional elevation raster passed to fly_footprint(), sizing each frame from its height above ground instead of the reported scale. See the Terrain section of fly_footprint().

Value

A tibble with the grouping column, n_photos, covered_km2, and coverage_pct.

Examples

centroids <- sf::st_read(system.file("testdata/photo_centroids.gpkg", package = "fly"))
#> Reading layer `photo_centroids' from data source 
#>   `/home/runner/work/_temp/Library/fly/testdata/photo_centroids.gpkg' 
#>   using driver `GPKG'
#> Simple feature collection with 20 features and 16 fields
#> Geometry type: POINT
#> Dimension:     XY
#> Bounding box:  xmin: -126.7631 ymin: 54.34512 xmax: -126.449 ymax: 54.47635
#> Geodetic CRS:  WGS 84
aoi <- sf::st_read(system.file("testdata/aoi.gpkg", package = "fly"))
#> Reading layer `aoi' from data source 
#>   `/home/runner/work/_temp/Library/fly/testdata/aoi.gpkg' using driver `GPKG'
#> Simple feature collection with 1 feature and 0 fields
#> Geometry type: MULTIPOLYGON
#> Dimension:     XY
#> Bounding box:  xmin: -126.75 ymin: 54.34813 xmax: -126.45 ymax: 54.47
#> Geodetic CRS:  WGS 84
fly_coverage(centroids, aoi, by = "scale")
#> Spherical geometry (s2) switched off
#> Spherical geometry (s2) switched on
#> # A tibble: 2 × 4
#>   scale   n_photos covered_km2 coverage_pct
#>   <chr>      <int>       <dbl>        <dbl>
#> 1 1:12000       10        14.8         59.5
#> 2 1:31680       10        24.8        100