Thermal GSD and flight distance check

Defaults: DJI Zenmuse H20T thermal camera (640 x 512, 12 um pixel, 13.5 mm lens, DJI specs page, October 2026) and a 6 x 18 half-cell module (Qcells Q.TRON BLK M-G2+, 1722 x 1134 mm). Thresholds are the figures quoted by secondary sources for IEC TS 62446-3, not text we read in the standard. Design aid only.

Pixel pitch (um)

Focal length (mm)

Image width (pixels)

Image height (pixels)

Cell short side (mm)

Cell long side (mm)

Minimum pixels per cell side

Maximum GSD (cm/pixel)

Camera-to-module distance (m)

Angle off the module normal (degrees)

Angle: 0 when the camera looks straight at the module face. A camera looking straight down at modules tilted 25 degrees is about 25 degrees off the normal. Pixels are counted in the stretched direction, a cautious choice.