Remote Sensing
Radiometric calibration
The characterisation that converts raw sensor counts into physical radiance so measurements are comparable across sensors and time.
Sensors drift. Detectors age, optics degrade and gains shift. Calibration tracks these changes so that the same ground target yields the same value years apart.
Well-calibrated archives allow analysts to combine sensors, extend records backward and compare a project with a nearby reference area without hidden instrument bias.
Frequently asked questions
Why does drift matter for carbon work?
Small drifts compound across a time series and can appear as gradual vegetation change.
Do commercial providers calibrate?
Quality varies. Cross-calibration against reference sensors is the usual check.