Custom sensor direction


I’ve started to work with cesium and i have wanted to make a beam(sensor) that comes out of a satellite.

My satellite is in an orbit that’s make the satellite be above the earth in the same spot all the time.

Now, I want to make like a signal beam from a satellite to a *random point on earth(in the field of view of the satellite) and see how the beam intersects with earth. My beam is a cone shape.

I looked up in the sensors example and i only managed to get my sensor to start from my satellite position but cant get it to point in the direction of my *random point on earth and that way to intersects with it.

*By random point i mean i have an event that gets the point of the place i clicked on earth with cesium widget.

I would appreciate your help.

Basically I have 2 points in the world one is the satellite and the other one is a point on the ellipsoid and i want to make a cone sensor from the satellite to the point on the ellipsoid.

How do I make the model matrix of the sensor so it will to go from the satellite to the point on the ellipsoid?

I'm dredging this up from the depths because I'm in the same boat. I have two positions, one in space and one on the earth. I can draw a sensor from the point in space to the center of earth using the northEastDownToFixedFrame transform just fine. I can't figure out which transform or Matrix function to use to rotate the sensor to point to the position on earth.

I do have the quaternion for the position in space so if I can utilize that in czml instead then perhaps I'll go the czml route, but right now I was just trying to get it working programmatically.

I know the sensors aren't supported anymore but this is really a question of how to utilize the various transforms and matrix functions to get it to do what I want. Any help would be appreciated.

I am trying to use czml and I can not figure out how to get the quaternion to make the sensor point to the center of the earth. How do I get the quaternion from the Cartesian3 point of the satellite? Thanks.