Methods and algorithms for data exploitation of the imaging Fourier transform spectrometer GLORIA-AB on HALO - MaxiFTS -
Zusammenfassung der Projektergebnisse
A thorough characterisation of the GLORIA instrument has been performed within the DFG project MaxiFTS. A standardised level 1 processing from raw interferograms to calibrated spectra has been established, and the processing time has been optimised such that it is around or below flight duration. New methods have been developed especially in terms of detector characterisation and radiometric calibration approach. The instrument performance and the level 1 processing have been published in two peer-reviewed papers. Improvement of the radiometric calibration quality is expected by application of the new, pixel dependent non-linearity correction and homogenisation. Several pixels change their sensitivity drastically when changing the integration time. The identification and correction of these pixels will further improve the data quality. Another improvement is expected by the new calibration approach which uses the calibration measurements of the whole flight at once and combines the measurements with an instrument model taking the temperature variation of several instrument components into account. Especially the contribution of the entrance window to the radiometric offset is better captured by the model taking the window temperature into account than by simple linear interpolation. The possibility to use all calibration measurements for the determination of the gain function largely improves the signal to noise ratio and makes the gain determination insensitive to variations of the window temperature which in the current approach is a leading error source for the gain, especially at the beginning of a flight.
