Availability of Data for Synergy between Hyperspectral Space Missions

Abstract

Challenge: In April 2025, the DLR Earth Sensing Imaging Spectrometer (DESIS) completed seven years of operations onboard the International Space Station (ISS). The DESIS mission was developed as a collaboration between Teledyne Brown Engineering (TBE, USA) and the German Aerospace Center (DLR, Germany). 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 and holds the potential for multisensory data analysis that uses synergies of the spaceborne missions involved. Until October 2023, DESIS has recorded more than 265.000 scenes covering large parts of the terrestrial Earth prioritizing repeated acquisitions of selected key targets. For some areas, it results in more than 120 available scenes across several years and seasons.

Materials & Methods: We will provide an overview ofthe DESIS mission status, calibration and data quality and data access. The priority of this talk will be on an update of the available acquisitions up to February, 2025 to highlight hot spot areas of acquisitions and to prepare the ground for the matchup analysis with other missions. A graphical overview of the coverage and density of DESIS data will be developed and analysed. Based on available metadata of spaceborne hyperspectral missions, we define different matchup rules, that could be discussed in the community. Based on these rules, we mapped overlays with other spaceborne hyperspectral missions such as EMIT, EnMAP and PRISMA (if available). The results of these matchups are presented in terms of location and density of the matchups (see Figure 1).

Results: Due to the long lifetime of the mission, the archive is one of the largest available hyperspectral image archives. It shows coverage of large parts of the Earth surface. Moreover, certain areas are covered in multiple yearly and seasonal observations. The results provide a user-oriented view on the data coverage and availability and shall inform the user community about available test data for multitemporal and multisensorial data analysis. The heatmap data as well as the matchups will be provided to inform users and to facilitate international cooperation.

Outlook: The matchups are potential starting points for data fusion developments, which could be of high interest for complementary missions. As an example, the location of both DESIS and EMIT on the ISS has provided a high number of simultaneous acquisitions, namely ~8000 image coincidences with less than 1% clouds over 1 year. As DESIS has higher spatial (30 m) and spectral resolution (~2.5 nm) compared to EMIT (60 m and 10 nm, respectively), data fusion could be performed, focusing on the VNIR range and verifying the possibility of extending the model to the SWIR, which is missing in DESIS, by exploiting the spatial and spectral correlation of the bands and n eighbouring pixels in both datasets. The main benefit of fusing these products lies in the different swath width of the sensors, which would result in images with 30m GSD across the entire EMIT footprint, which is 2.5 larger with respect to DESIS.