Systems and methods for reading Radio Frequency Identified (RFID) tags. In an embodiment, an enclosure having, within it, an antenna and processor is provided. The processor may be configured to record tag observations for tag identifiers received by the antenna from RFID tags. For one or more time intervals, tag observations may be identified which satisfy a tag filter, and a confidence that RFID tags satisfying the tag filter were in the field of view of the antenna during the time interval may be computed based on the identified tag observations. According to an embodiment, reports for tag filters may be then generated using the computed confidences, and these reports may be transmitted to an external system over a network.