A couple of years ago I had a DFU on a package delivered by another cover driver. The photo printout showed three little squares with Xs in them, the sup told me they represented where the diad was at the scan, at DR and stop complete. I can only guess this is done by long & lat as previously stated. The photo showed these Xs in a vacant lot two blocks away from the actual house. I know that the other cover driver may not have known where the house was (no addresses on that block), however I am pretty sure he didn't leave the package in a vacant lot and call it DR SD. I don't know what the problem was with gps, diad, or whatever, but the data that UPS was going on was WRONG.
Our center still doesn't have telematics, so that isn't to blame.