Does the technology allow this level of precision?
It would be very difficult to do this, unfortunately, as no passive or active RFID technology is that precise. The only possible way would be to create a grid of very small high-frequency (HF) antennas, and then, when a tagged item was at a specific spot, have that antenna read the tag, thereby enabling you to know precisely where the item was located. To create a sizable grid would be costly, however, as you would need a high volume of readers to connect the antenna grid to.
—Mark Roberti, Founder and Editor, RFID Journal
What Are the Requirements for Certifying RFID Equipment? »