Multi-sensor architectures for thermal imaging missions

Among the innovative offerings that NewSpace companies bring to the space industry, one is a constellation of thermal instruments.

Thermal infrared (TIR) imagers are inherently more challenging to calibrate and geolocate than visible and near-infrared (VNIR) instruments due to:
• lower spatial resolutions
• higher sensor noise levels; and
• a scarcity of stable reference features.

This makes radiometric and geometric modelling more complex. Multi-sensor satellite architectures that co-locate VNIR and TIR imagers are increasingly valuable for Earth observation applications. These applications require accurate, timely surface temperature data. Integrating reflective and emissive sensors on a single platform can potentially enable improved geometric precision and radiometric consistency.

Our goal with this research is to evaluate whether multi-sensor architectures can enhance the geolocation accuracy of lower-resolution TIR sensors when combined with higher-resolution VNIR imagers through cross-calibration and shared spatial models. We explore how a combination of visible and thermal data can streamline processing workflows for bottom-of-atmosphere products, enabling rapid and reliable insights. Multi-sensor solutions have their advantages, but also pose challenges, such as time-synchronisation between imagers and onboard systems. Acquiring reference data with common features across spectral bands for spatial calibration remains difficult.
Our findings will state the strengths and limitations of each method. We will present results from multiple space missions with different instruments on board. These results will help to inform the design of future thermal imaging constellations.