This function allows the user to create a degrees grid based on an input bounding box
degrees_to_global_grid(
minx = -180,
maxx = 180,
maxy = 90,
miny = -90,
degrees = 1,
square_geoms = TRUE,
crs_value = 4326,
verbose = FALSE
)the 'minx' parameter of the bounding box
the 'maxx' parameter of the bounding box
the 'maxy' parameter of the bounding box
the 'miny' parameter of the bounding box
a numeric value specifying the degrees. It defaults to 1.0
a boolean. If FALSE then a hexagonal grid will be created
a value. The coordinate reference system of the output grid. The crs must correspond to the EPSG of the input 'minx', 'maxx', 'miny' and 'maxy'. Moreover, the 'EPSG:4326' returns a degrees grid as output.
a boolean. If TRUE then information will be printed out in the console
a simple features (sf) object
The default global input 'minx', 'maxx', 'miny' and 'maxy' correspond to a WKT of "POLYGON ((-180 -90, 180 -90, 180 90, -180 90, -180 -90))" When 'minx', 'maxx', 'miny' and 'maxy' EPSG is lat,long (or 'EPSG:4326') I expect the output grid to be in 'degrees' unit. Using an EPSG other than 'EPSG:4326' might return a different output unit (such as meters). See also the following 'Stackoverflow' thread for more information, https://stackoverflow.com/a/64903836/8302386
Based on 'Approximate Metric Equivalents' 1 degree is approximately 111 km (or 60 nautical miles), Reference: https://www.usna.edu/Users/oceano/pguth/md_help/html/approx_equivalents.htm
if (FALSE) {
require(IceSat2R)
#...........................................
# 'OpenAltimetry' allows 1x1 degree bounding
# box selection for the 'atl03' Product
#...........................................
gl_grid_1_d = degrees_to_global_grid(degrees = 1.0, verbose = TRUE)
gl_grid_1_d
# summary(gl_grid_1_d$area)
#...........................................................................
# 'OpenAltimetry' allows 5x5 degree bounding box selection for the following
# Products: 'atl06', 'atl07', 'atl08', 'atl10', 'atl12', 'atl13', 'level3a'
#...........................................................................
gl_grid_5_d = degrees_to_global_grid(degrees = 5.0, verbose = TRUE)
gl_grid_5_d
}