PHOTOMETRY AND RADIOMETRY
Photometric Calibration. The process of converting instrumental magnitudes to calibrated apparent magnitudes in a stan- dard system is generally referred to as ‘photometric calibration’. The level of complexity at which. this is done is dependent to a great extent on the quality of data which one has.
Radiometric Calibration refers to the ability to convert the digital numbers recorded by satellite imaging systems into physical units. Those units are either radiance (W/m2/sr/µm) or apparent top-of-atmosphere reflectance.