Correction of Airborne IR-Scanner Data

Abstract

The radiant emission of water surface recorded by IR-scanners is afflicted with various errors. Sources of error are described and suggestions for their elimination are given. In one example a radiometrically determined temperature distribution is compared with one measured conventionally.

The radiant emission of a water surface recorded by an IR-Scanner is afflicted with various errors. In many application orientated cases, it is sufficient to extricate the horizontal temperature gradients from the IR images so that only the scan angle dependent limb darkening effect has to be empirically corrected. On the other hand, if one is interested in quantitative temperature values, there are two courses that can be adopted. In order to avoid extensive numerical procedures, quite frequently only an empirical correction is applied, which is statistically determined from a number of sea-truth observations. A second, more exact, method is the determination or estimation of the different physical effects which can cause errors in the IR images. Some examples of the latter method are given in the following.

This work was carried out as part of the Erdwissenschaftliches Flugzeumeβprogramm, sponsored by the Federal Ministry for Research and Technology in Bonn, FRG.