I am not sure if I can get any help here on this one but i am going to throw it out there. I time races using an RFID system. Last week we timed our first race with an overhead gantry system. It was a 20' span over the starting line that we covered with 6 evenly spaced antennas. The first 4 antennas were on one reader and the last two were on another reader. We tested all of our equipment prior to the event and all was working.
During the race we only had a 75% read rate with the vast majority of our reads coming from the outside antennas and almost none coming from the antennas between them. The antennas were in a line and aimed downward.
Does anyone have the expertise to tell me why this might have happened? Our RFID system routinely reads well over 99% at the finish line (using antennas embedded into mats that the runners run across) so this 75% rate is totally unacceptable.