5 Years of the Spaceborne Hyperspectral DESIS Mission, A Growing Archive for Monitoring the Earth

Kurzfassung

On August 2023, the DLR Earth Sensing Imaging Spectrometer (DESIS) completed five years of operations onboard the International Space Station (ISS). The DESIS mission has been developed as a collaboration between Teledyne Brown Engineering (TBE, USA), providing the platform, infrastructure for operations and data tasking, and the German Aerospace Center (DLR, Germany), which designed and built the instrument and software for data processing and delivery. The DLR is also responsible for the validation and scientific exploitation of the mission. DESIS has been acquiring data worldwide for both scientific and commercial users. The continuously growing data archive supports methodical and application developments for the monitoring of the Earth’s surface. One of the major objectives of the mission is preparing the ground for the upcoming hyperspectral operational mapping missions from ESA (CHIME) and NASA (SBG). The data acquired by DESIS exhibit unique features with respect to other running and upcoming missions. First, the data archive is characterized by multitemporal acquisitions with varying observation and illumination conditions, an issue that requires specific consideration within the processors, especially the atmospheric correction, in order to meet the requirements regarding data quality. Second, DESIS covers the visible to the near-infrared range with extremely narrow bands, resulting in a spectral sampling of 2.55 nm. This enables novel scientific fields such as investigating the suitability of DESIS data for detecting Solar Induced Fluorescence (SIF) emitted by plants during photosynthesis. Further studies have been proposed in the energy sector (e.g. solar panel area estimation) and landscape archeology. Third, the complex characteristics of the ISS orbit do not merely represent a limit for its observation capabilities, but at the same time enable the acquisition of information usually not available for sun-synchronous platforms, such as the investigation of processes related to photosynthesis at different times of the day, or the dynamics of coastal and inland water systems. DESIS is currently operating in nominal conditions, further expanding its multitemporal data archive, which holds great value for a wide range of applications and serves as a database for recent and upcoming hyperspectral Earth-observing missions. It enables long-term analysis of physical phenomena and land use changes by extending both temporal range and resolution for the monitoring of a site of interest.