General vertical perspective projection
lat = 41.5; lon = -74; alt = 160; tilt = 0; azim = 0; twist = 0; width = 0; height = 0;
coast(region=:global360, frame=(annot=5, grid=5), land=:lightbrown, water=:lightblue,
shore=true, borders=((level=1,pen=(1,:red)), (level=2, pen=0.5)),
proj=(name=:ortho, center=[lon, lat], parallels=[alt, azim, tilt, twist, width, height]),
figsize=10, yshift=12, xshift=2.5)
# Now point from an altitude of 160 km with a specific tilt and azimuth and with a wider restricted
# view and a boresight twist of 45 degrees
tilt=55; azim=210; twist=45; width=30; height=30;
coast!(frame=:same, land=:lightbrown, water=:lightblue, shore=true,
rivers=(level=:a, pen=:blue), res=:intermediate, borders=:a,
proj=(name=:ortho, center=[lon, lat], parallels=[alt, azim, tilt, twist, width, height]),
figsize=12, xshift=2.5, yshift=-10, show=1)
See also GMT ex26