Range and motion sensor

I need to detect an object, a person actually, which may be at a distance of 2m and moving from side to side. At any time, I would like to be able to determine at what angle from my detection point, this person is.

I am animating an object so that once it detects someone within a certain range (my question assumes a 2m circle from the central point, but maybe it could be 3m), that the object rotates so the person is directly (0 degrees) in front of this object.

I have saved several links that use Ping sensors. But those solutions assume that the transmitter of one sensor is disabled so the ultrasonic pulse from only one Ping is detected by both modules.

While this may work, it’s a kludge. The transmitters are triggered simultaneously, but the transmitter of one sensor is blocked physically.

Anyone have a better idea to try? I’m not married to any one technology. I need to activate two sensors, get the distance from both and triangulate the position of the person.

Any and all suggestions are welcome!

Thanks

One additional piece of information. The two sensors can be a maximum of 7cm apart. Except when they’re not. A less than optimal solution placed the sensors 14cm apart..,

Man -- that's some confusing description. So, you need to detect people in a 360° horizontal range, at a distance of 2 to 3 meters? Is "detection point" synonymous with "central point"?

djsfantasi:
The two sensors can be a maximum of 7cm apart. Except when they’re not. A less than optimal solution placed the sensors 14cm apart..

So, in other words, 7cm, and any other distance, except 14cm?!? And, if you're "not married to any one technology", then why the "2 sensor" constraint? WTF?!?
Maybe a diagram, or three? Also, I get the impression you want the detection rate to be as fast as human perception, or faster? And, at what frequency, and resolution?

Does this animation interact with the people being detected? How? It might be important to know this, because of the animation technology's potential for interfering a sensor technology.

This smacks of potential x-y problem, so it would be great if you read: How To Use This Forum

The two sensors can be a maximum of 7cm apart. Except when they're not.

That nails it right down.