Radiometric calibration

However, for gamma ray and X-ray dose measurements a unit such as the gray or sievert is normally used.

The following table shows ionising radiation quantities in SI and non-SI units.

Spectral data acquired by satellite sensors are influenced by a number of factors, such as atmospheric absorption, scattering, sensor-target-illumination geometry, sensor calibration, and image data processing procedures, which tend to change through time.

[1] Targets in multi-date scenes are extremely variable and have been nearly impossible to compare in an automated mode.

The absolute approach requires the use of ground measurements at the time of data acquisition for atmospheric correction and sensor calibration.

Graphic showing relationships between radioactivity and detected ionizing radiation. The detecting instrument has to be radiometrically calibrated so it is traceable to national standards.