Detection accuracy

Same detector, same imagery, five match distances. Pick one — the tradeoff between finding more pools and flagging the wrong thing is real, not a chart trick.

The 94% precision figure is a one-county number (Maricopa County, AZ). It runs 74–82% in the two other counties tested — see the county page.

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recall

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false-alarm rate

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parcel precision

A separate check, not one of the five distances above. Before any shape or size filter is applied, a 40 m circle around a parcel is so big that about 3.9 detections fall inside it by chance alone. In that raw, unfiltered test — not the filtered "40 m" result shown above — it fires on 99.61% of parcels with a real pool and 93.92% of parcels without one, for only 5.7 points of real lift. That is why 40 m was dropped: a rule that fires on almost every parcel is measuring the neighborhood, not the parcel.

Source: measured on one Maricopa County, AZ aerial pass, 2026-07-26. n = 5,186 parcels with a recorded pool vs 17,661 residential parcels with none, one aerial photo covering 49.03 km².