I design ‘chips’ for a living and it’s not that simple.
The problem is that to accurately determine a 3D spatial position it can only be done optically as there isn’t a precise enough positioning technology available currently. GPS is not precise enough.
It is possible that in the future other radio based triangulation systems could be developed but nothing exists currently that has the required precision.
So optical is the only way at the moment which leads to the follow up problem that because time is a factor the measurement needed is actually 4D. Current broadcast video is 25 frames per second which means that there is uncertainty of 1/25 sec between frames. Clearly that time period is significant when people are using the system to accuracies of a few mm’s.
The system is fundamentally flawed until replaced by high resolution video systems which operate at higher fps. 60 Frames per second is available and used in industrial optical inspection systems and could be deployed in VAR if high speed networks were available. It’s still not perfect but higher FPS translates to more accurate position resolution.
VAR needs 60 FPS video connected to a facility within the ground via high speed direct fibre connections. This could easily be implemented using a facility similar to the post production trucks used by the TV broadcasters, these are the lorries that we see parked up outside the ground.
The tech could be easily implemented but they have chosen the cheap option of using the standard TV feeds and a central facility.
However, good a system is however, let’s be in no doubt that it would be used to fuck us over at every opportunity.