#xtics must be numerically assending
xtics: -180, -70, -50.5, -30, -10, 30, 180
#ytics must be numerically descending
ytics: 90, 80, 60, 40, 20.1, 0, -60, -90

radius_grid:
9	5	5	5	5	5	5
5	5	5	5	5	5	5
5	5	5	5	5	5	5
5	5	3	2	5	5	5
5	5	5	5	5	5	5
5	3	5	5	5	1	5
5	5	5	5	5	5	5
5	5	5	5	5	5	5
