Raw to Calibrated Data

The actual transformation of raw detector data to clean maps in intensity scale depends strongly on both the imaging and detecting systems. However, three typical steps can be identified, namely: detection and removal artifacts in the data, correction for non-linear effects or relative variations in sensitivity of the detector system, and correction for geometric distortions in the imaging device. Although the order of the first two steps can often be interchanged the geometric correction must be performed last because it involves a rebinning of the data which assumes them to be intensities.