File:Central meridian.svg

1 	Point NS(0.72, -0.65, 2.5) 	  	NS = (0.72, -0.65, 2.5) 	 
2 	Point M 	Intersection point of zAxis, xOyPlane 	M = (0, 0, 0) 	 
3 	Sphere sun 	Sphere through NS with center M 	sun: x² + y² + z² = 7.19 	 
4 	Point C 	Intersection point of sun, zAxis 	C = (0, 0, -2.68) 	 
5 	Point D 	Intersection point of sun, zAxis 	D = (0, 0, 2.68) 	 
6 	Point vp1(-2.68, 0, 0) 	Intersection point of sun, xAxis 	vp1 = (-2.68, 0, 0) 	 
7 	Point vp2(2.68, 0, 0) 	Intersection point of sun, xAxis 	vp2 = (2.68, 0, 0) 	 
8 	Circle d 	Circle through D, vp2, C 	d: X = (0, 0, 0) + (1.9 cos(t) - 1.9 sin(t), 0, -1.9 cos(t) - 1.9 sin(t)) 	 
9 	Line r 	Line M, NS 	r: X = (0, 0, 0) + λ (0.72, -0.65, 2.5) 	 
10 	Plane eqp 	Plane through M perpendicular to r 	eqp: 0.72x - 0.65y + 2.5z = 0 	 
11 	Circle eq 	Intersection curve of eqp, sun 	eq: X = (0, 0, 0) + (1.79 cos(t) - 1.86 sin(t), 1.99 cos(t) + 1.67 sin(t), 0.98 sin(t)) 	 
12 	Point S 	NS mirrored at Plane(eq) 	S = (-0.72, 0.65, -2.5) 	 
13 	Circle c 	Circle through NS, vp2, S 	c: X = (0, 0, 0) + (1.62 cos(t) - 2.14 sin(t), 0.54 cos(t) + 0.41 sin(t), -2.07 cos(t) - 1.57 sin(t)) 	 
14 	Point A 	Intersection point of c, eq 	A = (2.58, 0.18, -0.7) 	 
15 	Point B 	Intersection point of c, eq 	B = (-2.58, -0.18, 0.7) 	 
16 	Vector ra 	Vector(-1.5NS, 1.5NS) 	ra = (2.17, -1.96, 7.49) 	 
17 	Point MP 	Point on eq 	MP = (2.34, 1.26, -0.35) 	 
18 	Arc zm 	CircumcircularArc(NS, MP, S) 	zm = 8.42 	 
19 	Line T21 	Tangent to d through vp2 	T21: X = (2.68, 0, 0) + λ (0, 0, -2.68) 	 
20 	Text text1 	  	"N_S" 	 
21 	Point NE(0, 0.2, 3.8) 	  	NE = (0, 0.2, 3.8) 	 
22 	Text text2 	  	"N_E"