Thermal pixel footprint

Model: IFOV = pixel pitch ÷ focal length when not given; footprint = IFOV × distance; the smallest reliable target spans the rule's pixels (3 × 3 by default, FLIR guidance), and the farthest distance for a target is its size ÷ (pixels × IFOV)

Show your work

1. Smallest reliable target

   $$\mathrm{pixels}\times \mathrm{IFOV}\times \mathrm{distance}$$

   3 × 1.3 mrad × 30 m = 117 mm

2. Pixel footprint

   $$\mathrm{IFOV}\times \mathrm{distance}$$

   1.3 mrad × 30 m = 39 mm

The same steps an agent gets from the MCP server with explain: true.

Accuracy: Geometry only. Atmosphere, optics blur, and emissivity also limit what a thermal camera reads; the 3 × 3 rule is industry guidance, not a standard

Worked example: A 1.3 mrad camera at 30 m. Source: add-practitioner-essentials solar-panel scenario: 39 mm pixel footprint, 117 mm smallest target by the 3 × 3 rule. It is golden test vector v001, and every build checks the tool still gives its answer within its tolerance.

Review: Not yet independently reviewed by a Part 107 remote pilot.

Last verified: 2026-09-22, when a maintainer last confirmed this tool's sources at the issuer. See the sources ledger.

Status: version 1.0.0, core 0.1.0. See this tool in the verification report.

Checked against: 6 golden test vectors (download the test vectors, each with its source and tolerance). See how results are checked and every source.

Sources

• How Far Can You Measure with a Thermal Camera?, Teledyne FLIR, Web article, 2023-09-12. At least 3 × 3 pixels on a target for an accurate temperature measurement.

Terms

IFOV: instantaneous field of view

The angle one detector pixel sees, usually in milliradians; times the distance, it is the patch of surface that pixel covers. Source: How Far Can You Measure with a Thermal Camera?

Experimental means this tool has not yet met the stable bar: at least 20 golden vectors, differential tests, and an independent worked example.