def downloads_for(self, tile):
tiles = set()
# if the tile scale is greater than 20x the SRTM scale, then there's no
# point in including SRTM, it'll be far too fine to make a difference.
# SRTM is 1 arc second.
if tile.max_resolution() > 20 * 1.0 / 3600:
return tiles
# buffer by 0.01 degrees (36px) to grab neighbouring tiles and ensure
# that there aren't any boundary artefacts.
tile_bbox = tile.latlon_bbox().buffer(0.01)
tile_index = self._ensure_tile_index()
for t in index.intersections(tile_index, tile_bbox):
tiles.add(t)
return tiles
def downloads_for(self, tile):
tiles = set()
# if the tile scale is greater than 20x the NED scale, then there's no
# point in including NED, it'll be far too fine to make a difference.
# NED13 is 1/3rd arc second.
if tile.max_resolution() > 20 * 1.0 / (3600 * 3):
return tiles
# buffer by 0.0075 degrees (81px) to grab neighbouring tiles and ensure
# some overlap to take care of boundary issues.
tile_bbox = tile.latlon_bbox().buffer(0.0075)
tile_index = self._ensure_tile_index()
for t in index.intersections(tile_index, tile_bbox):
tiles.add(t)
return tiles
def downloads_for(self, tile):
tiles = set()
# if the tile scale is greater than 20x the NED scale, then there's no
# point in including NED, it'll be far too fine to make a difference.
# NED13 is 1/3rd arc second.
if tile.max_resolution() > 20 * 1.0 / (3600 * 3):
return tiles
# buffer by 0.0075 degrees (81px) to grab neighbouring tiles and ensure
# some overlap to take care of boundary issues.
tile_bbox = tile.latlon_bbox().buffer(0.0075)
tile_index = self._ensure_tile_index()
for t in index.intersections(tile_index, tile_bbox):
tiles.add(t)
return tiles
def downloads_for(self, tile):
tiles = set()
# if the tile scale is greater than 20x the SRTM scale, then there's no
# point in including SRTM, it'll be far too fine to make a difference.
# SRTM is 1 arc second.
if tile.max_resolution() > 20 * 1.0 / 3600:
return tiles
# buffer by 0.01 degrees (36px) to grab neighbouring tiles and ensure
# that there aren't any boundary artefacts.
tile_bbox = tile.latlon_bbox().buffer(0.01)
tile_index = self._ensure_tile_index()
for t in index.intersections(tile_index, tile_bbox):
tiles.add(t)
return tiles
