December 6, 2025Open Access

Versatile FourierTransform Spectrometer Model for Earth Observation Missions Validated with In-Flight Systems Measurements

TPTom PiekarskiEuropean Space Research and Technology Centre FFFelix Friedl-VallonKarlsruhe Institute of Technology

Key Points

Results indicate less than 2% difference between model predictions and measured signals, confirming accuracy.
Validation focuses on the radiometric performance of FTS instruments in Earth observation contexts.
The approach employs in-flight measurements from the GLORIA-Lite spectrometer for model assessment.
Future missions may benefit from this confirmed model, supporting enhanced atmospheric monitoring.

Abstract

Fourier-transform spectrometers (FTSs) are cornerstone instruments in Earth observation space missions, effectively monitoring atmospheric gases in missions such as Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), and Infrared Atmospheric Sounding Interferometer (IASI). It will also be the core instrument of Meteosat Third Generation—Sounding (MTG-S) and the future Earth Explorer (EE) mission Far-infrared Outgoing Radiation Understanding and Monitoring (FORUM). Building on this legacy, the European Space Agency (ESA) has developed an FTS instrument and an inverse model designed to estimate the radiometric and spectral performance from a set of instrumental parameters. The model and its validation using in-flight measurements of the FTS instrument Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA)-Lite are described in this paper. The results indicate that the difference between the model predictions and the measured signal is less than 2% relative to the average of the measurements. Moreover, we can correctly predict the instrument’s radiometric gain and offset and reconstruct a scientific science spectrum. This model can be utilised effectively to evaluate the radiometric performance of future FTS missions.

KI fragen

Bookmark

View Full Paper