Whew… Found it.
Took me a while but I found some of what I was looking for.
IR beacon and docking
https://www.robotshop.com/letsmakerobots/node/22347
Triangulation via IR beacon
https://www.robotshop.com/letsmakerobots/node/6499
WOO HOO I FOUND THE GOOD ONE!! Here’s how it’s done --watch the video below
Wow Thanks a lot! Can’t say
Wow Thanks a lot! Can’t say anything more 
I dunno if you saw in the videos or not
The basic idea (shown in all the videos above) is a 38khz sensor, inside of a tube. That’s it. The “beacons” simply spit-out a IR TV signal --I am actually using “volume up”, I think. The tube around the sensor allows the sensor to only see what is directly in front of it,making it directional. I have tried different sized tubes, different lengths, I have painted some black on the inside. I have also allowed the sensor to be uncovered and shielded the beacon (to make the beacon directional --shooting only one way). All of these configurations have led to varying results. The overall idea is that when the tube gets smaller, the sensor is far more pin-point accurate, but will have a much harder time finding the beam. --This is true both vert. and horz.
You will have to play with it a bit.
