set title 'Worst-Case Differential Airmass vs Airmass'
set xrange [1:5]
set xlabel 'Airmass'
set yrange [0:0.1]
set grid xtics ytics
set parametric
plot [t=pi/2:0.2] \
	1/sin(t), 1/sin(t-0.018)-1/sin(t) title 'sep=1 deg',\
	1/sin(t), 1/sin(t-0.009)-1/sin(t) title 'sep=30 min',\
	1/sin(t), 1/sin(t-0.0045)-1/sin(t) title 'sep=15 min',\
	1/sin(t), 1/sin(t-0.003)-1/sin(t) title 'sep=10 min',\
	1/sin(t), 1/sin(t-0.0018)-1/sin(t) title 'sep=6 min',\
	1/sin(t), 1/sin(t-0.0009)-1/sin(t) title 'sep=3 min',\
	1/sin(t), 1/sin(t-0.0003)-1/sin(t) title 'sep=1 min'