Can I use radio frequency identification to track an object to within only a few inches?
—Gerry O'Malley

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Gerry,

Generally speaking, it is impossible to read a tag from 1000 feet, or even 30 feet, away and pinpoint an object's location to within a few inches. RFID systems typically locate an object's general position, or determined whether it has passed through a particular portal. On the other hand, there are systems that can identify individual vials in a holder, even when they are inches apart. So it really depends on your application.

Mark Roberti, Editor, RFID Journal