Calculate intersection of line from known origin with DTED

I’m working on calculating a point on the ground where a camera is pointing from a drone.

I’ve got DTED2, and can extract the position / altitude of the drone as well as the az/el angles of the camera boresight.

What I’d like to return (ideally using python) is a lat/Lon and elevation for the point where the camera boresight intersects the DTED. Very little experience of working with DTED so be gentle!