project_to_hemisphere: Identidy visible points on an arbitrary global hemishpere view.
Description
Given a global hemispheric field of view defined by a single latitudinal and longitudinal centroid focal point, project geographic points onto the hemishpere.
Usage
project_to_hemisphere(lon, lat, lon0, lat0)
Arguments
lon0
longitude of focus coordinates.
lat0
latitude of focus coordinates.
Value
returns a data frame.
Details
project_to_hemisphere identifies whether each pair of coordinates in the lat and lon vectors is in a field of view defined by a centroid focal point (lat0, lon0)
and returns a data frame containing the original coordinates and a column indicating if the coordinates are in the field of view (TRUE or FALSE).