Tools · EO/IR payloads

DRI range calculator

Detection, recognition and identification ranges of an EO/IR camera under NATO STANAG 4347, computed from its sensor and optics, with the assumptions behind every figure.

Example camera. Replace the values with your own: every result updates as you type.

Visible · 0.4–0.7 µm

Day channel

Include

Pixel pitch (µm) Focal length (mm) Horizontal pixels

Aperture (f-number) Wavelength (µm) Demosaicing factor (colour sensor; 1 = no loss)

LWIR · 8–14 µm

Thermal channel

Include

Pixel pitch (µm) Focal length (mm) Horizontal pixels Sensor NETD (mK)

Aperture (f-number) Wavelength (µm)

Meteorological visibility (km)

Include atmosphere Stabilization residual (µrad)

Day channel

Target inherent contrast Contrast threshold

Thermal channel

LWIR extinction (per km) Target-to-background ΔT (K, STANAG 4347: 2) Threshold (multiple of NETD)

Results

Ranges

Generated from your inputs

Justification

Reference

Method and assumptions

Vehicle, NATO STANAG 4347 (defence). Standard target 2.3 × 2.3 m (main battle tank, front view), 1 / 3 / 6 cycles for detection, recognition and identification, 2 K target-to-background difference. Applied to the day channel as well, as NATO has no equivalent for visible cameras.
Person, defence. STANAG 4347 defines no person target; defence EO/IR datasheets apply the same 1 / 3 / 6 cycles to a standing person with a 0.75 m critical dimension.
Person, video surveillance, IEC 62676-4:2014 (DORI) (civil). 25 / 125 / 250 pixels per metre on the person to detect, recognise and identify an individual; far more demanding than the defence convention, and independent of target size.
Drone and custom target. No standard defines them: the STANAG 1 / 3 / 6 cycles are applied to the size you enter.
Pixel field of view IFOV = pixel pitch / focal length, divided by the demosaicing factor on a colour sensor; the diffraction spot 1.22 × λ × N / focal length applies as a limit when it is larger; stabilization residual added in quadrature.
Cycles: R = critical dimension / (pixels × system IFOV), with 2 pixels per cycle. Pixel density: R = 1 / (density × system IFOV).
Atmosphere: day R = V / 3.912 × ln(C0 / Cthreshold) (Koschmieder); thermal R = ln(ΔT / (k × NETD)) / σ. Each range is the shorter of the geometric range and this limit.
A nominal static estimate, not a measured performance: turbulence, lens MTF beyond diffraction, day-channel noise, video compression and observer performance are not modelled. Confirm on a bench (resolution, NETD) and in the field at surveyed distances.