I have the following problem:
There is a sphere (Earth) and a cone (the FOV of a satellite orbiting Earth). So the tip of the cone is at the satellite's center orbiting Earth, and the wide part of the cone is intersecting with Earth's surface. The center axis of the cone is always pointing towards Earth's center, so the intersection between the cone and the sphere is a circle on the sphere's surface.
So far so good.
Now, what I am looking for is a way to calculate a condition which defines which points on the sphere's surface are inside this intersecting circle.
I.e. a closed condition which allows me to define if a point on Earth's surface is inside the FOV of the satellite.
The "circle of intersection" can easily be defined by it's center and it's radius. But I am struggeling with the next step to formulate a condition out of this for points on the sphere's surface that are inside this contured fraction of the sphere. So I am dreaming of the possibility to say: "for this cone and this sphere, all points on the sphere's surface with coordinates (which kind of coordinates ever) that are within the range a to b... are visible."
I hope it's at least a bit clear what I am looking for :)
I would highly appreciate any input and ideas on this.
Thanks and Cheers, af_ab